Biomedical subjects

I H Chaudry

Publications and source records attributed to I H Chaudry.

At least 145 records · Page 8Linked to original sources

PubMed1997

Trauma-hemorrhage induces increased thymic apoptosis while decreasing IL-3 release and increasing GM-CSF.

Although the thymus is an important organ in the ontogeny of T lymphocytes, little is known about the effects of hemorrhage and/or trauma on this organ. The objective of this study was to determine whether trauma-hemorrhage induces increased thymic apoptosis and, if so, which mediators may be involved. Male C3H/HeN mice underwent either sham operation, hemorrhagic shock (mean artery blood pressure of 35 +/- 5 mmHg for 90 min, followed by blood and fluid resuscitation), fracture of the right tibia, or fracture plus hemorrhage, respectively. At 3 days after the procedure, total viable thymocyte yield, thymocyte apoptosis (flow cytometry), thymus-derived IL-3 (bioassay), and GM-CSF (ELISA) were determined. The results demonstrate that fracture alone induces no significant change in the parameters measured. However, (i) there was a significant decrease in total viable thymocyte yield and an increase in thymocyte apoptosis following hemorrhage or fracture plus hemorrhage; (ii) thymocyte IL-3 release was significantly reduced after hemorrhage as well as fracture plus hemorrhage; (iii) thymus-derived GM-CSF was significantly increased after fracture plus hemorrhage, but not with hemorrhage alone. In conclusion, severe hemorrhage alone or coupled with fracture can induce thymus atrophy via apoptosis. In addition, the decreased IL-3 release suggests that apoptotic thymic involution may be due to the lack of growth factor support. Such dyshomeostasis may contribute to inappropriate/inadequate T cell maturation leading to host immune suppression following trauma-hemorrhage. Increased thymus-derived GM-CSF might be in part responsible for the systemic inflammatory response following trauma-hemorrhage.

Animals↗

PubMed1997

Mechanism of hepatocellular dysfunction during early sepsis. Key role of increased gene expression and release of proinflammatory cytokines tumor necrosis factor and interleukin-6.

BACKGROUND: Hepatocellular dysfunction occurs at 1.5 hours after cecal ligation and puncture (CLP [ie, sepsis model]), despite normal cardiac output and hepatic perfusion. OBJECTIVE: To determine whether proinflammatory cytokines such as tumor necrosis factor (TNF) and interleukin-6 (IL-6) are up-regulated before the occurrence of hepatocellular dysfunction during sepsis. DESIGN, INTERVENTION, AND MAIN OUTCOME MEASURE: Rats were subjected to sepsis by CLP, followed by administration of normal saline solution, 3 mL/100 g of body weight, to these and animals undergoing sham operation. At 0.5, 1, 1.5, or 2 hours after CLP, circulating levels of TNF and IL-6 were measured by enzyme-linked immunosorbent assay and bioassay, respectively. In additional animals, Kupffer cells were isolated at 1, 2, or 5 hours after CLP or sham operation. Kupffer cell TNF and IL-6 messenger RNA levels were determined by reverse-transcription polymerase chain reaction technique. RESULTS: Plasma levels of TNF and IL-6 increased significantly at 1.5 hours and persisted at 2 hours after CLP. Levels of TNF and IL-6 messenger RNA in Kupffer cells increased as early as 1 hour after CLP. The up-regulated gene expression also persisted at 2 and 5 hours after the onset of sepsis. CONCLUSIONS: We have previously shown that TNF-alpha infusion produces hepatocellular dysfunction and that pharmacological inhibition of TNF production prevents it. Since the present study demonstrated that upregulation of proinflammatory cytokine gene expression occurs before hepatocellular dysfunction during sepsis, TNF and/or IL-6 may be responsible for producing hepatocellular dysfunction. Thus, administration of pharmacologic agents that selectively block or inhibit proinflammatory cytokine release may be useful in preventing cellular dysfunction during early sepsis.

Animals↗

PubMed1997

Testosterone receptor blockade after hemorrhage in males. Restoration of the depressed immune functions and improved survival following subsequent sepsis.

BACKGROUND: Recent studies suggest that androgen depletion by castration before hemorrhage has protective effects on cell-mediated immunity in male mice after soft tissue trauma and hemorrhagic shock. OBJECTIVE: To determine whether treatment with an androgen receptor blocker (eg, flutamide) after trauma-hemorrhage and sepsis has any salutary effects on cell-mediated immunity and on the survival of male animals under those conditions. DESIGN: Male C3H/HeN mice were either sham operated or subjected to hemorrhagic shock (mean [+/- SEM] blood pressure, 35 +/- 5 mm Hg for 90 minutes) followed by adequate fluid resuscitation (with shed blood and lactated Ringer solution). The animals then received either vehicle or 25-mg/kg body weight flutamide subcutaneously immediately after the resuscitation as well as 24 and 48 hours thereafter. At 48 hours after shock, sepsis was induced by cecal ligation and puncture. Sham-operated animals underwent laparotomy only. At 24 hours after cecal ligation and puncture, the animals were killed, blood was collected, and splenocytes and splenic macrophages were harvested to produce nonadherent and adherent cultures. Splenocytes were evaluated for splenocyte proliferation and interleukin 2 release, while interleukin 1 and interleukin 6 release were assayed in splenic macrophages. Plasma testosterone and corticosterone levels were also measured by radioimmunoassay. In a separate set of experiments, survival was measured over a period of 9 days after the induction of sepsis. RESULTS: Hemorrhage followed by sepsis produced a significant (P < .05) depression of splenocyte and macrophage functions in vehicle-treated animals. In contrast, animals treated with flutamide showed markedly improved immune functions, as evidenced by restoration of splenocyte proliferation, interleukin 2 release, splenic macrophage interleukin 1 release, and improvement of splenic macrophage interleukin 6 release. Plasma corticosterone levels were notably elevated while testosterone levels were depressed after hemorrhage and the induction of sepsis. The survival rate of the animals in the flutamide-treated group was also notably higher than the survival rate of animals in the vehicle-treated group subjected to hemorrhage and sepsis. CONCLUSION: The findings that flutamide not only markedly improves the depressed immune functions but also the survival of animals after hemorrhage and the induction of sepsis suggest that the short-term administration of androgen receptor blocker in males after trauma represents a safe and novel approach for preventing immune deficiency and decreasing the mortality rate from subsequent sepsis.

Androgen Antagonists↗

PubMed1997

Effects of prolactin and metoclopramide on macrophage cytokine gene expression in late sepsis.

Previous studies indicate a profound suppression of tumour necrosis factor alpha (TNF-gamma), IL-1 beta and IL-6 release capacity by peritoneal macrophage (PM phi), splenic macrophage (SM phi) and Kupffer cells (KC) during late sepsis. Such a loss of functional capacity may reduce the animal's ability to ward off infection. Prolactin is known to enhance monocyte, T- and B-lymphocyte immune responses under normal conditions and has beneficial effects on cell-mediated immunity after haemorrhage. In the respect, the dopamine antagonist, metoclopramide, has been reported to increase circulating prolactin levels. Nonetheless, it remains unknown whether prolactin or metoclopramide have any salutary effect on macrophage (M phi) cytokine gene expression following sepsis. To study this, male C3H/HeN mice were subjected to sepsis and immediately thereafter were treated with prolactin (100 micrograms/25 g body weight, s.c.), metoclopramide (100 micrograms/100 g BW, s.c.) or given saline. PM phi, SM phi and KC (only SM phi and KC in metoclopramide-treated animals) were isolated at 24 h after sepsis. The monolayers were stimulated with or without LPS 10 micrograms/ml for 1 h in vitro. Total RNA was extracted and mRNA was detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). A significant depression of constitutive and inducible mRNA levels of IL-1 beta, IL-6 and TNF-alpha in all three M phi populations were observed, when compared with shams (with exception of KC IL-6 mRNA in unstimulated cells). Prolactin as well as metoclopramide treatment after the onset of sepsis caused significant elevation of constitutive and inducible cytokine gene expression in all macrophages examined. Thus, prolactin and metoclopramide enhance the depressed M phi gene expression and may be useful in improving cell-mediated immunity during sepsis.

Animals↗

PubMed1997

Factors responsible for peritoneal granulocyte apoptosis during sepsis.

Apoptosis (Ao), is a process by which cells undergo a form of non-necrotic cellular suicide, the control of which may have significant impact on host immunoresponsiveness to a septic challenge. The aim of this study was to determine (1) if Ao is evident in granulocytes harvested from the blood or peritoneum of septic animals and to what extent this was associated with cell activation and (2) whether the in vivo administration of the TNF inhibitor (TNFbp) alters this process. To assess the first aim, C3H/HeN male mice were subjected to polymicrobial sepsis [cecal ligation and puncture (CLP)] or sham-CLP (Sham) and sacrificed at 4 or 24 hr following CLP. Blood leukocytes and peritoneal exudate cells were harvested, stained with monoclonal fluorochrome-conjugated antibodies to granulocytes (Gr1), the activation marker ICAM-1, and either the cell cycle dye, 4',6-diamidino-2-phenylindole, or TUNEL assay (to assess the %Ao+), was used for two- and three-color flow cytometric analysis. Peritoneal exudate cells exhibited increased %Ao+ cells at both 4 and 24 hr post-CLP, while blood leukocytes showed a decrease in %Ao+ only at 24 hr. The increase in Ao in the peritoneum was evident only in the Gr1- cell population at 4 hr but was present in both Gr1+ and Gr1- cells at 24 h. Furthermore, the increase in the %Ao+ cells was associated with an increased % of ICAM-1 positive cells. To the extent that TNF affects the 24 hr induction of Ao in peritoneal exudate cells, mice were treated with either 250 micrograms TNFbp/mouse (s.c.) or vehicle control immediately following CLP. The results indicate that administration of TNFbp markedly decreased Gr1+ but not Gr1- cell Ao. Thus, not only does polymicrobial sepsis induce a marked early rise in phagocyte Ao associated with cell activation, but the increase in peritoneal granulocyte Ao, unlike macrophage Ao, is mediated by TNF and/or an agent released by TNF.

Animals↗

PubMed1997

Administration of ATP-MgCl2 after trauma-hemorrhage and resuscitation restores the depressed cardiac performance.

Although adenosine triphosphate (ATP)-MgCl2 has been shown to improve cardiac performance under normal and postischemic conditions, it is not known whether this agent has any salutary effects on cardiac performance following trauma-hemorrhage and crystalloid resuscitation. To determine this, rats underwent laparotomy (i.e., trauma induction) and were bled to and maintained at a mean arterial pressure of 40 mm Hg until 40% of the maximum shed blood volume was returned in the form of Ringer's lactate. The animals were then resuscitated with four times the volume of shed blood using Ringer's lactate over 60 min and received either ATP-MgCl2 (50 mumole/kg body wt) in 1 ml volume or an equivalent volume of normal saline intravenously over 95 min. Maximum dP/dt during contraction as well as relaxation (+/-dP/dtmax) and ventricular peak systolic pressure (VPSP) were determined 15 min prior to the end of resuscitation and every 30 min thereafter for 4 hr after the completion of resuscitation. The results indicate that both -dP/dtmax and +dP/dtmax decreased significantly beginning at 0 and 2 hr after the completion of resuscitation, respectively, and remained depressed throughout the duration of the study in saline-treated animals. In addition, VPSP was significantly depressed at 2-4 hr after resuscitation. Treatment with ATP-MgCl2, however, restored these parameters. Moreover, the depressed heart rate was also restored following ATP-MgCl2 administration. Since ATP-MgCl2 restores various left ventricular performance parameters, this agent appears to be a promising adjunct for improving cardiac function after trauma and hemorrhage, even in the absence of blood resuscitation.

Adenosine Triphosphate↗

PubMed1997

Mechanism of intestinal mucosal immune dysfunction following trauma-hemorrhage: increased apoptosis associated with elevated Fas expression in Peyer's patches.

Although intestinal mucosal immune dysfunction occurs after trauma and hemorrhage and appears to contribute to infectious complications, the mechanism is not known. In this regard, the inappropriate induction of immune cell apoptosis may contribute to the immune dysfunction following trauma and hemorrhage. To study this, we examined Peyer's patch cells for evidence of apoptosis and changes in Fas protein expression, as well as alterations in the relative lymphocyte subpopulations after trauma and hemorrhagic shock. Male C3H/HeN mice underwent sham operation, trauma (i.e., laparotomy), hemorrhagic shock (mean arterial blood pressure of 35 +/- 5 mmHg for 90 min, followed by adequate crystalloid resuscitation), or trauma plus hemorrhage. Peyer's patch cells were isolated at 24 and 72 hr after the procedure. The percentage of apoptotic cells, Fas protein expression, and cell percentage of phenotype were determined by flow cytometry. The results indicate that trauma alone induced no significant change in the measured parameters. However, (i) there were a significant decrease in total viable cell yield and an increased apoptosis in Peyer's patch cells at 24 and 72 hr following hemorrhage or trauma plus hemorrhage; (ii) the increased apoptosis in Peyer's patch was predominantly in cells of the B-cell lineage; (iii) the increased apoptosis was associated with an elevated Fas expression. In conclusion, hemorrhage alone or trauma plus hemorrhage can induce increased apoptosis in Peyer's patch cells, which is associated with the increased Fas expression. Thus, apoptotic involution may play an important role in the depression of intestinal mucosal immune function after trauma and hemorrhagic shock.

Animals↗

PubMed1997

The role of neutrophils in producing hepatocellular dysfunction during the hyperdynamic stage of sepsis in rats.

Although studies have shown that hepatocellular function is depressed during the early, hyperdynamic stage of sepsis, the mechanism responsible for this remains unknown. To determine whether neutrophils play any role in producing this depression, hepatocellular function was measured in neutrophil-competent and neutropenic animals subjected to sepsis. Neutropenia was induced by tail vein injection of an immunoglobulin directly against rat neutrophils (anti-neutrophil Ig) at 16 and 2 h prior to the initiation of cecal ligation and puncture (CLP, i.e., a model of polymicrobial sepsis). Neutropenia was confirmed by peripheral blood smears. Neutrophil-competent controls were given nonimmunized Ig before the onset of sepsis. Sham-operated animals received anti-neutrophil Ig or control Ig. Hepatocellular function [i.e., the maximal velocity of indocyanine green clearance (Vmax) and efficiency of the clearance (Km)] was determined by a fiber-optic catheter and in vivo hemoreflectometer at 5 h after CLP (i.e., early, hyperdynamic sepsis) or sham operation. Serum alanine aminotransferase (ALT) levels were also determined. The results indicate that although circulating levels of ALT were not elevated, hepatocellular function was significantly depressed during early sepsis. The depression in Vmax and Km was, however, prevented by neutrophil depletion, suggesting an integral role of the neutrophils in depressing hepatocellular function under such conditions. The results suggest that the prudent modulation of neutrophil function during the early stage of polymicrobial sepsis may be beneficial for preventing or delaying the occurrence of hepatocellular dysfunction.

Alanine Transaminase↗

PubMed1997

Females in proestrus state maintain splenic immune functions and tolerate sepsis better than males.

OBJECTIVES: To determine: a) whether the cell-mediated immune response during sepsis differs in females vs. males; and b) whether the survival rate in females is different than in males after a septic insult. DESIGN: A prospective, randomized animal study. SETTING: University research laboratory. SUBJECTS: Male and female proestrus C3H/HeN mice. INTERVENTIONS: After anesthesia, male and proestrus female mice underwent cecal ligation puncture to induce sepsis. The mice were killed at 24 hrs after the onset of sepsis. MEASUREMENTS AND MAIN RESULTS: Splenocyte proliferation, as well as splenocyte interleukin (IL)-2 and IL-3 release, was determined by bioassay. In additional studies, survival rate after septic challenge was measured over 10 days. Splenocyte proliferative capacity and splenocyte IL-2 and IL-3 release were markedly decreased in male, but not in female, septic mice. Furthermore, the survival rate of septic female proestrus mice was significantly higher than in comparable male mice. CONCLUSIONS: These results support the concept that the immune response of females differs from males, and that females are immunologically better positioned to meet the challenge of sepsis.

Adolescent↗

PubMed1997

Pentoxifylline maintains hepatocellular function and improves cardiac performance during early sepsis.

BACKGROUND AND OBJECTIVE: Although pentoxifylline (PTX) produces various beneficial effects after endotoxemia, it remains unknown whether this agent attenuates the depressed hepatocellular function and improves heart performance during early sepsis. The aim of this study, therefore, was to determine whether PTX maintains hepatocellular function and improves cardiac function during the early hyperdynamic stages of polymicrobial sepsis. DESIGN, MATERIALS, AND METHODS: Rats were subjected to sepsis by cecal ligation and puncture (CLP). At 1 hour after CLP, PTX (50 mg/kg body weight), or an equal volume of saline, was infused intravenously over 30 minutes. At 2 or 5 hours after CLP (i.e., early hyperdynamic stages of sepsis), hepatocellular function was assessed by in vivo indocyanine green clearance. Cardiac output was determined by dye dilution. Left ventricular performance parameters such as maximal rates of left ventricular pressure rise and fall (+/-dP/dtmax), ventricular peak systemic pressure, etc., were determined using a heart performance analyzer. RESULTS: The results indicate that hepatocellular function was significantly depressed at 2 and 5 hours after CLP. Administration of PTX, however, maintained hepatocellular function to sham levels. Although cardiac output increased after CLP with or without PTX treatment, this agent markedly improved cardiac performance as evidenced by significantly higher + dP/dtmax and ventricular peak systemic pressure as well as other heart performance parameters. CONCLUSIONS: Pentoxifylline appears to be a useful adjunct for maintaining hepatocellular function and improving cardiac performance during the early hyperdynamic stages of polymicrobial sepsis.

Animals↗

PubMed1997

Mechanism of splenic immunosuppression during sepsis: key role of Kupffer cell mediators.

Studies indicate that the liver, in particular the Kupffer cells, appear to be key contributors in the systemic inflammatory mediator response associated with shock and sepsis. Although several of these agents have been implicated as mediators of depressed immunoresponsiveness observed during sepsis, it remains unknown whether or not mediators released specifically by Kupffer cells play any significant role in producing the cellular dysfunction in distant organs. The aim of this study, therefore, was to determine whether or not acute Kupffer cell reduction before the onset of sepsis would protect splenic lymphocyte function. Kupffer cell number was reduced by prior (48 hours) treatment of mice with gadolinium chloride (GdCl2, 10 mg/kg of body weight, intravenously) or saline vehicle. Animals were then subjected to either sham-CLP (sham) or polymicrobial sepsis in the form of cecal ligation and puncture (CLP). Plasma and splenocytes were harvested at 2 or 24 hours after CLP. Splenocyte cultures were exposed to 2.5 micrograms concanavalin A/mL to assess their ability to release lymphokines. Cytokine (interleukin (IL)-2, IL-6, interferon-gamma, tumor necrosis factor-alpha) concentration in plasma or cell supernatants was assessed by bioassay. The results indicated that GdCl2 treated mice exhibited a marked reduction in circulating IL-6 levels at both 2 and 24 hours after CLP. Furthermore, the reduction of Kupffer cell number before the onset of sepsis completely prevented the depression of splenocyte IL-2 and interferon-gamma release, capacity. Thus mediators released by Kupffer cells during the systemic inflammatory response to polymicrobial sepsis play a significant role in producing immune dysfunction in resident splenic lymphocytes. In view of this, it appears that modulation of Kupffer cell hyperactivity during sepsis may be a novel approach for maintaining distant organ host defense mechanisms.

Animals↗

PubMed1997

Impaired enterocyte triglyceride synthesis after trauma-hemorrhage and resuscitation.

Although gut lipid absorptive capacity is depressed after trauma and hemorrhagic shock, it remains unknown whether this is associated with an impairment in the enterocyte triglyceride (TG) synthesis, and if so, whether villus or crypt cells participate in the lipid absorption under such conditions. To study this, midline laparotomy (i.e., trauma induction) was performed in the rats, and then the animals were bled to and maintained at a mean arterial pressure of 40 mmHg until 40% of shed blood volume was returned in the form of Ringer's lactate. The rats were then resuscitated with four times the volume of maximal bleedout with Ringer's lactate over 60 min. For lipid loading test, 1 mL of olive oil was given intraduodenally as a bolus injection upon the completion of resuscitation. The enterocytes along the crypt-villus axis from the proximal small intestine were isolated at either 0, 1.5, or 5 h after fat feeding. The intracellular and pre-chylomicron TG contents as well as the microsomal enzyme activities associated with TG synthesis were determined thereafter. The results indicated that intracellular and pre-chylomicron TG contents and lipid esterifying enzyme (i.e., acyl-coenzyme A:monoglyceride acyltransferase) activity decreased significantly in villus tip cells after trauma-hemorrhage and resuscitation. The intracellular TG content and lipid esterifying enzyme activity in crypt cells after trauma and hemorrhagic shock were also reduced. However, there was no significant decrease in pre-chylomicron TG content in the crypt cells isolated from trauma-hemorrhaged rats. It is unlikely that crypt cells participate in lipid transport after trauma and hemorrhagic shock. In contrast, the TG synthesis in villus tip cells decreased significantly following trauma-hemorrhage and resuscitation, which may contribute, at least in part, to the impaired gut lipid absorptive capacity observed under such conditions.

Animals↗

PubMed1997

Male sex steroids are responsible for depressing macrophage immune function after trauma-hemorrhage.

Recent studies suggest beneficial effects of castration before soft tissue trauma and hemorrhagic shock on splenocyte immune functions. Nonetheless, it remains unknown whether this effect of testosterone depletion is limited to splenocytes or is a generalized effect on immune function. The present study was therefore carried out to determine whether androgen depletion before trauma-hemorrhage also has salutary effects on splenic and peritoneal macrophage as well as on Kupffer cell function, as indicated by interleukin (IL)-1 and IL-6 release. Male C3H/HeN mice were castrated or sham-castrated 2 wk before the experiment and were killed at 24 h after trauma-hemorrhage and resuscitation. Significant depression of macrophage IL-1 and IL-6 release was only observed in sham-castrated mice, as opposed to normal levels of cytokine release from castrated animals after trauma-hemorrhage. In addition, only sham-castrated animals showed significantly increased levels of IL-6 release from Kupffer cells, which is believed to contribute to the systemic inflammatory response to trauma-hemorrhage. These observations suggest that the beneficial effects of androgen depletion before trauma-hemorrhage are not limited to splenocyte immune functions but are more global in nature. These results in surgically castrated animals suggest that androgen-blocking agents should be studied for their potential to reverse the immunodepression associated with trauma-hemorrhage.

Androgens↗

PubMed1997

Salutary effects of ATP-MgCl2 on altered hepatocyte signal transduction after hemorrhagic shock.

Although previous studies indicate that hepatocyte P2 purinoceptors, macrophage adenosine 3',5'-cyclic monophosphate (cAMP), and beta-adrenergic receptors decrease after hemorrhage and that administration of ATP-MgCl2 after hemorrhage normalizes these parameters, it is not known whether other aspects of hepatocyte signal transduction processes, such as transmembrane coupling, are also affected by hemorrhage and, if so, whether ATP-MgCl2 has any beneficial effects on signal transduction. To study this, rats underwent a 5-cm midline laparotomy (i.e., trauma induced) and were bled to and maintained at a mean arterial pressure of 40 mmHg until 40% of a maximum bleed-out volume was returned in the form of Ringer lactate (RL). They were then resuscitated with three times the volume of shed blood with RL over 45 min followed by two times the volume with RL+ATP-MgCl2 (50 mumol/kg body wt) or an equivalent volume of saline over 95 min. Hepatocytes were isolated at 4 and 27 h after resuscitation, and basal as well as stimulated levels of cAMP and inositol 1,4,5-trisphosphate (IP3) were determined. The results indicate that basal levels of cAMP decreased whereas IP3 increased after hemorrhage and resuscitation. Receptor-dependent stimuli (i.e., glucagon and vasopressin) failed to elicit cAMP or IP3 accumulation after hemorrhage. In contrast, receptor-independent stimulation was not impaired. ATP-MgCl2 treatment, however, prevented the decreased basal levels of cAMP and IP3 and the ability of hepatocytes to respond to receptor-dependent stimulation. Thus ATP-MgCl2 treatment of animals after trauma-hemorrhage and resuscitation attenuates the impaired second messengers cAMP and IP3 and their membrane transduction processes.

1-Methyl-3-isobutylxanthine↗

PubMed1997

Testosterone receptor blockade after trauma-hemorrhage improves cardiac and hepatic functions in males.

Although studies have shown that testosterone receptor blockade with flutamide after hemorrhage restores the depressed immune function, it remains unknown whether administration of flutamide following trauma and hemorrhage and resuscitation has any salutary effects on the depressed cardiovascular and hepatocellular functions. To study this, male rats underwent a laparotomy (representing trauma) and were then bled and maintained at a mean arterial pressure (MAP) of 40 mmHg until the animals could not maintain this pressure. Ringer lactate was given to maintain a MAP of 40 mmHg until 40% of the maximal shed blood volume was returned in the form of Ringer lactate. The rats were then resuscitated with four times the shed blood volume in the form of Ringer lactate over 60 min. Flutamide (25 mg/kg) or an equal volume of the vehicle propanediol was injected subcutaneously 15 min before the end of resuscitation. Various in vivo heart performance parameters (e.g., maximal rate of the pressure increase or decrease), cardiac output, and hepatocellular function (i.e., the maximum velocity and the overall efficiency of indocyanine green clearance) were determined at 20 h after resuscitation. Additionally, hepatic microvascular blood flow (HMBF) was determined using a laser Doppler flowmeter. The results indicate that left ventricular performance, cardiac output, HMBF, and hepatocellular function decreased significantly at 20 h after the completion of trauma, hemorrhage, and resuscitation. Administration of the testosterone receptor blocker flutamide, however, significantly improved cardiac performance, HMBF, and hepatocellular function. Thus flutamide appears to be a novel and useful adjunct for improving cardiovascular and hepatocellular functions in males following trauma and hemorrhagic shock.

Androgen Antagonists↗

PubMed1997

Intestinal alkaline phosphatase: role in the depressed gut lipid transport after trauma-hemorrhagic shock.

Although studies have indicated that the gut lipid absorptive capacity is impaired after trauma and hemorrhagic shock, the mechanism responsible for this remains unknown. The aim of this study, therefore, was to determine whether intestinal alkaline phosphatase (IAP) plays any role in the depressed gut lipid absorptive function observed under such conditions. To determine this, 5 cm midline laparotomy (i.e., trauma induced) was performed in the rats, and animals were then bled to and maintained at a mean arterial pressure of 40 mmHg until 40% of shed blood volume was returned in the form of Ringer's lactate. The rats were resuscitated with four times the volume of maximal bleedout with Ringer's lactate over 60 min. For in vivo lipid loading test, 1 mL olive oil was given intraduodenally upon the completion of resuscitation. The enterocytes were isolated at either 0, 1.5, or 5 h after fat feeding, and the soluble, membranous and pre-chylomicron (pre-CM) IAP activities as well as triglyceride contents were determined thereafter. The results indicated that the soluble IAP activity in the villus tip cells isolated from trauma-hemorrhaged rats increased significantly at 0, 1.5, or 5 h after fat feeding. The pre-CMIAP activity, however, decreased markedly in villus tip cells at 1.5 or 5 h after lipid administration, which was associated with the decreased pre-CM triglyceride contents in villus tip cells under such conditions. The altered IAP activity in villus tip cells, therefore, appears to play a role in the depressed gut lipid absorption and transport following trauma-hemorrhage and resuscitation.

Alkaline Phosphatase↗

PubMed1997

Flutamide: a novel agent for restoring the depressed cell-mediated immunity following soft-tissue trauma and hemorrhagic shock.

Recent studies indicate beneficial effects of androgen depletion in male mice, before trauma-hemorrhage on cell-mediated immunity following soft-tissue trauma and hemorrhagic shock. Nonetheless, it remains unknown whether androgen receptor blockade following the insult has any salutary effects. To study this, male C3H/HeN mice were either sham-operated or subjected to soft-tissue trauma (i.e., 2.5 cm midline laparotomy) followed by hemorrhagic shock (blood pressure 35 +/- 5 mmHg for 90 min) and then adequately resuscitated (shed blood and lactated Ringer's). Immediately after the completion of resuscitation, as well as 24 and 48 h thereafter, the animals received either vehicle, 10 mg/kg body weight (BW) flutamide or 25 mg/kg BW flutamide subcutaneously. At 72 h after resuscitation, all animals were killed. The spleens and peritoneal macrophages (M phi) were then harvested and cultures established to determine IL-2 and IL-3 release, splenocyte proliferative capacity, as well as splenic and peritoneal M phi IL-1 release. Moreover, plasma testosterone and corticosterone levels were measured. Our results indicate that trauma-hemorrhage resulted in significant depression of splenocyte and M phi functions in vehicle-treated and animals receiving 10 mg/kg BW flutamide. Treatment with 25 mg/kg BW flutamide following trauma-hemorrhage, however, resulted in levels of cytokine release which were comparable with those found in sham-operated animals. No significant alterations in plasma corticosterone and testosterone levels were observed in any of the experimental groups. These findings indicate that short-term therapy of males with the androgen receptor blocker, flutamide at 25 mg/kg BW, following trauma-hemorrhage has protective effects on immune functions. This protective effect is dose dependent, since 10 mg/kg BW flutamide did not produce significant salutary effects. Thus, flutamide represents a novel and safe agent for improving the depressed functions in male trauma patients suffering severe blood loss.

Animals↗

PubMed1996

Prolactin administration following hemorrhagic shock improves macrophage cytokine release capacity and decreases mortality from subsequent sepsis.

Although prolactin is reported to counteract the immunosuppressive effects of glucocorticoids, cyclosporine, and morphine, it remains unknown whether prolactin has any salutary effects on the depressed immune responses following severe hemorrhage. To study this, mice were bled to and maintained at a mean arterial pressure of 35 mm Hg for 60 min, then adequately resuscitated and divided into two groups. One group received saline vehicle, while the other group received prolactin (100 micro g/25 g body weight, s.c.) immediately before resuscitation. Two hours thereafter, peritoneal (pMphi) and splenic macrophages (sMphi) were harvested and assessed not only for their ability to release IL-1 and IL-6, but also for cytokine gene expression using semiquantitative reverse transcription and PCR. In an additional group, mice were subjected to sepsis by cecal ligation and puncture 3 days after hemorrhage. Hemorrhage markedly decreased the ability of pMphi and sMphi to release IL-1 and IL-6. This was, however, associated with increased mRNA expression for IL-1beta and IL-6 and increased serum corticosterone levels. Following prolactin treatment of hemorrhaged mice, IL-1beta and IL-6 mRNA levels as well as cytokine release capacity and blood corticosterone levels were comparable to the values in sham animals. Prolactin also improved the survival of animals subjected to sepsis after hemorrhage. Thus, the immunosuppression following hemorrhage appears to be mediated and modulated by hormones from the hypothalamic-pituitary-adrenal axis. Furthermore, prolactin represents a novel immunomodulating hormone for the treatment of immunodepression encountered after hemorrhagic shock and for decreasing the mortality from subsequent sepsis under those conditions.

Animals↗