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C W Smith

Publications and source records attributed to C W Smith.

At least 217 records · Page 12Linked to original sources
PubMed1993

Production of a monoclonal antibody against canine GMP-140 (P-selectin) and studies of its vascular distribution in canine tissues.

Rapid upregulation of the adhesion molecule GMP-140 (P-selectin) on endothelial cells is believed to play an important role in the initial binding of leukocytes to endothelium, a very early step in the inflammatory response. Activated platelets that are involved in the coagulation system and in inflammatory processes also express GMP-140 on their surfaces. The objectives of the present study were to develop a monoclonal antibody against this adhesion molecule in the dog and to use this antibody to study platelet-neutrophil interactions in whole blood and to characterize the in vivo localization of GMP-140 in canine tissues. Five Balb/c mice were immunized with thrombin-stimulated dog platelets, and clones were screened using an enzyme-linked immunosorbent assay. The clone MD3 (IgG1) showed preferential binding to activated as compared with resting platelets. Flow cytometric analysis using MD3 revealed that 27% of circulating neutrophils in unstimulated blood had platelets bound to their surfaces; stimulation with platelet activating factor increased this percentage to 85%. Immunoblot analysis of solubilized dog platelets resolved by sodium dodecyl sulfate polyacrylamide gel electrophoresis indicated that the antibody MD3 recognized an approximately 140-kd protein. Immunohistochemical study of normal dog tissues with MD3 revealed that the antigen was present in endothelial cells of arteries, capillaries, and veins, depending on the specific tissue examined. Blood vessels staining positively with MD3 were most abundant in the digestive system (liver, stomach, small and large intestines), moderate in the lungs, kidneys, spleen, lymph nodes, and endocrine glands, and minimal in the brain, myocardium, skeletal system, and skin. Based on its presence on stimulated but not resting platelets, its molecular weight, and its vascular distribution, the antigen recognized by MD3 appears to be the selectin GMP-140 of the dog. This study documents that the cellular and tissue distribution of GMP-140 in dogs is very similar to that in human beings.

Animals↗
PubMed1993

Neutrophil adhesion to endothelial cells.

The emigration of neutrophils at sites of inflammation apparently requires intercellular adhesion. Initially, leukocyte adherence is observed in postcapillary venules where neutrophils roll along the luminal surface of the endothelial cells before stopping, changing shape, and migrating into the perivascular tissue. Recent evidence indicates that the adhesion molecules supporting the rolling phenomenon are distinct from those required for stopping and transmigration. The contribution of E-selectin (ELAM-1) to neutrophil adhesion and rolling was investigated using anti-E-selectin monoclonal antibody in an in vitro adhesion assay of isolated human neutrophils to murine L-cell monolayers stably transfected with human E-selectin cDNA. Isolated human neutrophils adhered to E-selectin expressing L-cell monolayers under physiological wall shear stress of 1.85 dynes/cm2 but not to untransfected L-cells or ICAM-1 expressing L-cells. 47.8 +/- 6.0% of these adherent cells were rolling at an average rolling velocity of 10.6 +/- 1.7 microns/second. This adhesion and rolling was almost completely blocked by anti-E-selectin monoclonal antibody. Monoclonal antibody to L-selectin also reduced adhesion to E-selectin expressing cells by 70%. Chemotactic stimulation of neutrophils reduced both the number of adherent and rolling cells and the average velocity of the rolling cells without influencing the percentage of attached cells that were rolling. Pretreatment with anti-CD18 monoclonal antibody did not reduce the adhesion of the activated neutrophils but reversed the reduction in velocity caused by activation of these cells. The inhibitory potential of the anti-E-selectin monoclonal antibody was much less pronounced in adhesion of isolated neutrophils to human umbilical vein endothelial cell monolayers under conditions of flow and was limited to one third of the total adhesion. The proportion of the adherent neutrophils which transmigrated to the subluminal space of the endothelial cell monolayers was independent of pretreatment with anti-E-selectin monoclonal antibody.

Animals↗
PubMed1993

Molecular evidence for a border zone vulnerable to inflammatory reperfusion injury.

Acute inflammation has been suggested as a potential mechanism for some of the injury associated with reperfusion of the ischemic myocardium. This hypothesis implies that viable myocardial cells adjacent to the lethally injured cells are vulnerable to injury induced by the neutrophil influx observed to attend reperfusion. In our previous work, we demonstrated that the presence of ICAM-1 on the surface of cardiac myocytes is required for neutrophils to directly damage them; blocking monoclonal antibodies to either ICAM-1 on cardiac myocytes or Mac-1 on activated neutrophils completely precluded neutrophil-induced myocyte injury. We also demonstrated that postischemic cardiac lymph (cardiac extracellular fluid) contained leukotactic factors (primarily C5a) and cytokines present in concentrations sufficient to maximally induce Mac-1 on the surface of neutrophils and ICAM-1 on the surface of isolated dog cardiac myocytes. The present study sought to further these observations by examining the site of potential ICAM-1 induction as a function of time of reperfusion, degree of ischemia, and viability of myocardial cells. Our evidence suggests that ICAM-1 mRNA is induced very early after reperfusion only in the previously ischemic myocardium and is not seen in the nonischemic myocardium during the early hours of reperfusion. Moreover, ICAM-1 mRNA induction is seen most intensely in the ischemic area directly bordering the necrotic area (which, after 1-hr reperfusion, does not contain any ICAM-1 mRNA) and immediately abutting the site of maximal influx of neutrophils. Thus, the induction of ICAM-1 and the influx of neutrophils (presumably activated by the chemotactic factors that guided their migration) exists on the border between viable and necrotic cells. This provides the first direct molecular evidence for a jeopardized border zone on the edge of myocardial infarction during reperfusion. As previously demonstrated, this reaction is wholly dependent upon tissue injury of the ischemic myocardium and therefore represents an example of a mechanism of injury extension induced as a reaction to a primary injury. The degree of specificity of this reaction demonstrated by the subendocardial sparing directly adjacent to ischemic cells suggests finely modulated mechanisms by which this process is controlled.

Animals↗
PubMed1993

Monoclonal antibody against the CD18 adhesion molecule stimulates glucose uptake by the liver and hepatic nonparenchymal cells.

Neutrophils and macrophages play an important role in the body's microbicidal defense and have been implicated in the induction of tissue injury in reperfusion, endotoxemia and septic shock. Cellular host defense is accompanied by enhanced glucose use. In this study we examined the effect of monoclonal antibody 1F12 on in vivo glucose use by selected tissues and hepatic phagocytes. Monoclonal antibody 1F12 is specific for the CD18 adhesion molecule on rat neutrophils and is the only known antibody that induces profound neutropenia. The administration of monoclonal antibody 1F12 at a final dose of 2 mg/kg body weight enhanced the removal of neutrophils from the circulation within 15 min. Leukopenia was sustained for 24 hr. Large numbers of neutrophils were sequestered in the liver at 4 hr. Although the number of neutrophils in the liver at 24 hr after antibody treatment was lower than at 4 hr, these values were still higher than those in the saline controls. The rate of glucose metabolism by selected tissues was not significantly altered by the antibody, except by the liver, in which use increased 2.7-fold vs. the control value at 4 hr after treatment. Hepatocytes, endothelial cells and Kupffer cells contributed to the increase in the rate of glucose metabolism by the liver. The rate of glucose metabolism by Kupffer cells was significantly elevated at 4 and 24 hr, whereas the rate of glucose metabolism of hepatocytes and endothelial cells returned to normal at 24 hr. After antibody treatment, the glucose uptake by hepatic sequestered neutrophils was significantly reduced at 4 hr and returned to near-normal levels at 24 hr.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Role of beta 2 integrins and ICAM-1 in lung injury following ischemia-reperfusion of rat hind limbs.

Ischemia/reperfusion involving the hind limbs of rats results in both local injury to skeletal muscle as well as injury to lungs, as measured by increased vascular permeability (125I-labeled bovine serum albumin leakage) and hemorrhage (extravasation of 51Cr-labeled rat erythrocytes). In the current study, we have focused on events in lungs occurring during reperfusion of hind limbs. Analysis of blood neutrophils obtained 4 hours after reperfusion has indicated up-regulation of CD11b and CD18 but not CD11a. Plasma from the same animals demonstrate the ability to induce similar effects in normal blood neutrophils, indicative of the presence of a neutrophil-activating agent in plasma. During reperfusion, lung injury, which develops progressively over a 4-hour period, has been shown to be neutrophil-dependent and requires CD11a/CD18 and CD11b/CD18 as well as intercellular adhesion molecule-1. These data suggest that ischemia and reperfusion injury of rat lower extremities causes systemic changes that result in neutrophil-dependent lung injury that is beta 2 integrin- (leukocyte function antigen-1, Mac-1) and intercellular adhesion molecule-1-dependent.

Animals↗
PubMed1993

Leukocyte-endothelial cell interactions.

Mechanisms that support migration of leukocytes have been studied extensively in vitro. The adhesion of neutrophils under conditions of flow at venous shear rates primarily involves members of the selectin family. E-selectin is upregulated by cytokine stimulation of endothelial cells (ECs); P-selectin is upregulated by stimulation of ECs with agents such as thrombin and histamine; and L-selectin is resident on the surface of unstimulated neutrophils. Each selectin allows neutrophils to roll under conditions of flow. Rolling neutrophils often stop on the EC surface and then rapidly transmigrate. The stationary adhesions and migration are heavily dependent on two members of the CD18 (beta 2) integrin family, CD11a/CD18 and CD11b/CD18, on the neutrophil surface, intercellular adhesion molecule-1 (ICAM-1) on ECs, and endothelial-derived chemoattractants such as interleukin-8 (IL-8). Chemokinetic activation of neutrophils at the endothelial surface induces a transition from selectin-dependent adhesion to CD18/ICAM-1-dependent transmigration that is most clearly evidenced by the shedding of L-selectin from the neutrophil surface and upregulation of CD11b/CD18 to the neutrophil surface.

Amino Acid Sequence↗
PubMed1993

Functional inactivation of neutrophils with a Mac-1 (CD11b/CD18) monoclonal antibody protects against ischemia-reperfusion injury in rat liver.

The role of neutrophil CD11b/CD18 (Mac-1) adhesion proteins in the pathogenesis of hepatic reperfusion injury was investigated in an experimental model. Male Fischer rats were treated with a CD11b monoclonal antibody or an isotype-matched IgM control antibody and subjected to 45 min of hepatic ischemic followed by 24 hr of reperfusion. Large numbers of neutrophils were present in postischemic liver lobes (1,241 +/- 64 polymorphonuclear cells/50 high-power fields) compared with numbers in baseline measurements (14 +/- 3 polymorphonuclear cells/50 high-power fields), and severe liver injury was observed after 24 hr of reperfusion (hepatic necrosis: 88% +/- 2%). Pretreatment with the CD11b antibody (two doses of 2 mg/kg each significantly attenuated liver injury and reduced the number of polymorphonuclear cells in the post-ischemic liver by 59%. Selective treatment with the antibody only during reperfusion was similarly effective. The increased spontaneous superoxide formation of neutrophils isolated from postischemic liver (1.05 +/- 0.11 nmol O2-/hr/10(6) cells) was reduced by 56% in neutrophils from CD11b antibody-treated animals. Flow cytometric analysis of CD11b/CD18 expression on circulating neutrophils demonstrated significant upregulation at all time points during reperfusion. Clone 17 also effectively inhibited neutrophil extravasation in a glycogen peritonitis model. Our data are consistent with a dual protective effect of the CD11b antibody in hepatic reperfusion injury in vivo (i.e., reduced accumulation of neutrophils and their functional inactivation).

Animals↗
PubMed1992

Intercellular adhesion molecule-1 (ICAM-1)-dependent and ICAM-1-independent adhesive interactions between polymorphonuclear leukocytes and human airway epithelial cells infected with parainfluenza virus type 2.

Acute respiratory virus infections are often associated with an early influx of neutrophils (PMN) into the airways. Maximal cytoxic injury by PMN depends on tight cell-cell adhesion. Infection of some cell types by respiratory and other viruses has been shown to increase PMN adhesion to these cells by undefined mechanisms. We studied adhesion by human PMN to monolayers of primary (1 degree) human tracheal epithelial cells (TEC) or an immortalized cell line derived from human TEC, 9HTEo-, that had been infected with parainfluenza virus type 2 (PiV2). PMN adhesion to uninfected 1 degree TEC was very low (< 5%), but PMN adhesion to PiV2-infected 1 degree TEC was greatly increased (89 +/- 7%). PMN adhesion to 9HTEo- cells was 47 +/- 6%, but increased, 87 +/- 8%, for PiV2-infected 9HTEo- cells. Surface intercellular adhesion molecule-1 (ICAM-1) expression on 1 degree TEC, as determined by immunofluorescence flow cytometry, was relatively low (23 fluorescence units) but doubled by 24 h after PiV2 infection and tripled by 48 h. The 9HTEo- cells constitutively expressed higher levels of surface ICAM-1 (120 units) which did not increase with PiV2 infection. Treatment of non-PiV2-infected 9HTEo- cells with mAb (R6.5) to ICAM-1 reduced PMN adhesion to these cells from 47 +/- 8 to 23 +/- 5%. Identical mAb treatment of either 1 degree TEC or 9HTEo- cells infected with PiV2 had no significant effect on PMN adhesion. Treatment of the PMN with mAb against CD11a, CD11b, or CD18 markedly reduced PMN adhesion to PiV2-infected 1 degree TEC and 9HTEo- cells. We conclude that PiV2 infection of human TEC causes a marked increase in their adhesive interactions with PMN by inducing increased surface expression of both ICAM-1 and one or more, as yet uncharacterized, non-ICAM-1 adhesion molecules that function as counter-receptors for CD11/CD18 on PMN. These mechanisms of adhesion may play a role in epithelial damage during acute respiratory virus infections.

Adult↗
PubMed1992

A general method for the preparation of internally quenched fluorogenic protease substrates using solid-phase peptide synthesis.

A general scheme for obtaining a fluorescent donor/acceptor peptide substrate via solid-phase synthesis methodology is presented. The key feature of this method is the design of a glutamic acid derivative that has been modified on the carboxyl side chain with a 5-[(2'-aminoethyl)-amino]naphthelenesulfonic acid (EDANS) to create a fluorescent donor moiety that can be incorporated near the C-terminus of the peptide substrate. The corresponding fluorescent acceptor group containing a 4-[[4-(dimethylamino)phenyl]azo]benzoic acid (DABCYL) can then be attached to the resin-bound peptide at the N-terminus while all side-chain groups are still fully protected. Substrates for renin and HIV proteinase are synthesized as examples.

Amino Acid Sequence↗
PubMed1992

Subretinal fibrosis after laser photocoagulation for diabetic macular edema.

Seven eyes had subretinal fibrosis after grid laser photocoagulation for diabetic macular edema. The fibrosis caused persistent loss in visual acuity, and in six of the seven eyes, was not associated with detectable laser-induced Bruch's membrane rupture or subretinal hemorrhage. Choroidal neovascularization was detected in only one patient, who was notably younger (27 years) than the median age of 70 years in this series. The median preoperative visual acuity was 20/80 (range, 20/40 to 20/400); the median postoperative visual acuity was 20/400 (range, 20/80 to counting fingers). The subretinal fibrosis was detected at a median of three months (range, 14 days to 4 1/2 months) after laser therapy. In one of five bilaterally treated patients (20%), subretinal fibrosis developed in both eyes. Subretinal fibrosis may be caused by undetected choroidal neovascularization or by excessive proliferation after stimulation of an aged retinal pigment epithelium. Subretinal fibrosis may be a potential cause of loss in visual acuity after laser treatment for diabetic macular edema.

Adult↗
PubMed1992

Chemical synthesis of a biotinylated derivative of the simian immunodeficiency virus protease. Purification by avidin affinity chromatography and autocatalytic activation.

The protease from simian immunodeficiency virus (SIV) was chemically synthesized by automated solid-phase technology as an NH2-terminally extended derivative, capped with biotin. Biotin-linker-(SIV protease (1-99)): the linker segment, Gly-Gly-Asp-Arg-Gly-Phe-Ala-Ala, corresponds to the amino acid sequence preceding that of the protease in the SIV gag/pol precursor polyprotein. Accordingly, the Ala-Pro bond joining the octapeptide linker to the protease constitutes a site naturally cleaved by the protease during viral maturation. This strategy for synthesis was designed to facilitate purification of the biotinylated protein derivative from a complex mixture of reaction products by avidin/agarose-affinity chromatography and to provide the means for autocatalytic removal of the biotin-linker segment. As anticipated, folding of the full-length construct leads to activation of the enzyme and excision of the desired 99-residue SIV protease (overall yield, approximately). The specificity of the synthetic SIV protease toward a number of well characterized protein substrates was the same as observed for the nearly identical enzyme from human immunodeficiency virus type 2 (HIV-2 protease) and distinct from that of the more disparate HIV-1 protease. The same functional ordering with respect to the human retroviral proteases was reflected in Ki values observed with a number of protease inhibitors. Thus, the folded synthetic SIV protease shows patterns of specificity and susceptibility to inhibition that are in accord with what would be expected based upon its degree of structural similarity to proteases from HIV-1 and HIV-2.

Amino Acid Sequence↗
PubMed1992

Lung injury after deposition of IgA immune complexes. Requirements for CD18 and L-arginine.

Acute lung injury produced by deposition of IgA immune complexes is complement-dependent, neutrophil-independent, oxygen radical-mediated, and may be a result of the formation of the hydroxyl radical (HO) generated directly or indirectly from activated lung macrophages. The current studies were designed to evaluate further the pathophysiologic events that occur after intrapulmonary deposition of IgA immune complexes. Pretreatment of rats with the human recombinant soluble complement receptor-1 resulted in marked attenuation of IgA immune complex-induced lung injury. Intravenous administration of antibody to CD18, but not antibody to CD11b, was highly protective against lung injury. Treatment of animals with either anti-endothelial leukocyte-adhesion molecule-1 or anti-TNF-alpha, both of which were highly protective against IgG immune complex-induced lung injury, had no protective effects in the model of IgA immune complex-induced lung injury. Immunohistochemical analysis revealed up-regulation of the endothelial leukocyte adhesion molecule-1 in the pulmonary vasculature after deposition of IgA immune complexes. This up-regulation was TNF-alpha-dependent. The arginine analog, NG-monomethyl-L-arginine, was highly protective against IgA immune complex-induced lung injury. This protective effect was reversed by the co-presence of L-arginine (but not D-arginine). Protective interventions against IgA immune complex-induced lung injury were inversely correlated with the numbers of macrophages that could be retrieved by lung lavage. These data suggest fundamental differences in the pathogenesis of lung injury after intrapulmonary deposition of IgA immune complexes, as compared with injury caused by deposition of IgG immune complexes. In the latter, neutrophils, intrapulmonary generation of TNF-alpha, and up-regulation of pulmonary vascular endothelial leukocyte-adhesion molecule-1 are required for the full development of lung injury, whereas no such requirements appear in the case of IgA immune complex-induced lung injury. Full expression of IgA immune complex-induced lung injury also appears to require L-arginine, suggesting a possible role for nitric oxide or its derivatives in events ultimately leading to injury.

Animals↗
PubMed1992

Roles of beta 2 integrins of rat neutrophils in complement- and oxygen radical-mediated acute inflammatory injury.

The roles of beta 2 integrin molecules in neutrophil accumulation and tissue injury have been examined by the use of antibodies that are reactive with human CD11b and CD18 and cross-react with the homologous epitopes on rat neutrophils. Adherence to rat pulmonary artery endothelial cells by human neutrophils and endothelial cell killing by phorbol ester-activated human neutrophils required CD11b, CD11c, and CD18. Companion adherence studies between rat neutrophils and endothelial cells revealed a requirement for both CD11b and CD18. Neither anti-CD11b nor anti-CD18 depressed in vitro responses (O2- generation and chemotactic migration) of rat neutrophils. The accumulation of neutrophils in glycogen-induced peritoneal exudates was diminished substantially in rats treated with either anti-CD18 or anti-CD11b. In oxidant-mediated acute lung injury induced by rapid intravascular infusion of cobra venom factor, treatment of rats with either anti-CD18 or anti-CD11b significantly attenuated injury as assessed by increases in vascular permeability and hemorrhage. These protective effects correlated morphologically with diminished adhesion of neutrophils to interstitial intrapulmonary capillary endothelial cells. In studies of immune complex (BSA-anti-BSA)-induced alveolitis and dermal vasculitis, anti-CD18 had protective effects at all doses of anti-BSA employed. The protective effects of anti-CD18 correlated with diminished neutrophil accumulation in tissues at lower doses of anti-BSA. Although anti-CD11b was not effective under the same experimental conditions, intratracheal administration of this antibody conveyed protection against immune complex-induced lung injury, suggesting that both CD11b and CD18 are required for the full expression of injury. The current studies also demonstrated that when surface-bound IgG immune complexes were treated with fresh rat serum, the increment in O2- and TNF alpha generated by alveolar macrophages was suppressed by anti-CD18, but not by anti-CD11b, suggesting a heretofore unrecognized role for CD18 in the O2- and TNF-alpha responses of alveolar macrophages. Thus, neutrophil beta 2 integrins play a requisite role for the full expression of complement-dependent and oxygen radical-mediated injury of the lung and dermal vasculature.

Animals↗
PubMed1992

Role of pulmonary phagocytes in host defense against group B streptococci in preterm versus term rabbit lung.

Intrapulmonary clearance of group B streptococci (GBS) occurred in term rabbits 4 and 8 h after infection; GBS growth was evident in preterm rabbits at 8 h. Bronchoalveolar lavage revealed 17-fold higher numbers of pulmonary alveolar macrophages (PAM) in term versus preterm animals immediately after infection, whereas polymorphonuclear leukocyte (PMNL) recruitment was 13-fold greater in preterm than term rabbits at 8 h. Anti-CD18 monoclonal antibody R15.7 did not reduce PMNL influx or GBS killing in term animals. R15.7 failed to inhibit PMNL influx but augmented GBS growth in preterm animals. R15.7 significantly impaired GBS phagocytosis by preterm and term PMNL in vitro but had no effect on ingestion of GBS by preterm and term PAM. Thus, GBS infection initiates PMNL recruitment into lungs of preterm rabbits by CD18-independent mechanisms, but phagocytosis of GBS by PMNL is largely CD18-dependent. The poorer outcome of GBS pneumonia in preterm versus term newborns may result from low levels of PAM, thereby mandating recruitment of PMNL as a second phagocytic defense.

Animals↗
PubMed1992

Attitudes of medical students to old people: a cross-national comparative study.

Medical students' attitudes to the elderly were compared at the start and finish of a 5-week clinical attachment in health care of the elderly at the Christchurch School of Medicine. The study investigated students in their first clinical year (fourth year of their medical course) over five terms using a questionnaire employing a Rosencranz-McNevin semantic differential scale to measure general attitudes to old age and a Likert scale to measure attitudes to medical care. A question was also asked about career preferences. There was significant improvement in attitudes measured by both scales (Rosencranz-McNevin P less than 0.001, Likert P less than 0.001). Students also showed an increase in interest in health care of the elderly as a career choice. When compared with two cohorts of students from Nottingham Medical School, attitudes were significantly better in the Christchurch group at the commencement of the run. Students at both schools showed an improvement in knowledge but this was more marked for Christchurch students.

Aged↗
PubMed1992

Development and characterization of a cloned rat pulmonary arterial smooth muscle cell line that maintains differentiated properties through multiple subcultures.

BACKGROUND: Pulmonary hypertension is associated with abnormal pulmonary arterial contractility and growth. The mechanisms for these abnormalities are largely unknown. To study these processes, we sought to develop an in vitro system. Even though cultured aortic and pulmonary artery smooth muscle cells (SMCs) have been of considerable value in studying smooth muscle biology, one drawback of this system has been that these cells often lose differentiated properties in an unpredictable manner when they are passaged in culture. In addition, there appear to be significant differences in physiological and pathological responses between the systemic and pulmonary circulations, many of which could be directly related to the smooth muscle. We therefore established a cloned population of rat pulmonary arterial SMCs (PASMCs) that maintain differentiated properties through multiple subcultures. METHODS AND RESULTS: PASMCs were obtained initially by enzymatic dissociation from pulmonary arteries of adult Sprague-Dawley rats. From these cells, clones were isolated. The cloned cells retained expression of functional surface receptors for angiotensin II, norepinephrine, and alpha-thrombin and high levels of the smooth muscle isoforms of alpha-actin, myosin heavy chain, myosin regulatory light chain, and alpha-tropomyosin mRNAs even after multiple passages. The cells could also be transfected and processed exogenous transcripts in a smooth muscle-specific fashion. CONCLUSIONS: These cloned PASMCs retain many differentiated characteristics and should be valuable for future studies of pulmonary vascular smooth muscle cell biology.

Animals↗
PubMed1992

Kinetics of C5a release in cardiac lymph of dogs experiencing coronary artery ischemia-reperfusion injury.

Previous studies of myocardial ischemia suggest that complement activation may play a central role in the inflammatory response during reperfusion. Our previous work has demonstrated neutrophil chemotactic activity to be present in reperfusion canine cardiac lymph after myocardial ischemia and infarction. To evaluate the contribution of the complement-dependent anaphylatoxin C5a to this neutrophil chemotactic activity, rabbit antiserum to canine C5a was prepared. At dilutions > 1:500 but < 1:2,000, the antiserum abolished the ability of zymosan-activated dog serum to induce a ruffled, bipolar morphology in isolated neutrophils used as a bioassay of chemotactic stimulation. This antiserum did not affect similar morphological changes in neutrophils exposed to platelet activating factor (10(-7)-10(-6) M) or recombinant human interleukin-8 (10(-9)-10(-8) M); thus, we deemed it functionally specific for canine C5a. In a pattern similar to what we previously reported, cardiac lymph collected before a 1-hour ligation of the left circumflex coronary artery had little ability to alter the morphology of canine neutrophils (shape change index, 11.3 +/- 4.6, mean +/- SEM; n = 7), but by 1 hour of reperfusion, lymph activated neutrophils significantly in five of seven dogs (mean shape change index, 72.6 +/- 17.7; p < 0.01). At 2 hours of reperfusion, neutrophil activation by lymph occurred in six of seven dogs (mean shape change index, 103.1 +/- 22.2). At 3 hours of reperfusion, cardiac lymph of only three of six dogs caused neutrophil activation, and at 4 hours of reperfusion, this activity was evident in lymph from only two of five dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗