Biomedical subjects

T Almdal

Publications and source records attributed to T Almdal.

At least 19 recordsLinked to original sources

PubMed2006

A low-fat diet improves peripheral insulin sensitivity in patients with Type 1 diabetes.

AIMS: To compare the effects on insulin sensitivity, body composition and glycaemic control of the recommended standard weight-maintaining diabetes diet and an isocaloric low-fat diabetes diet during two, 3-month periods in patients with Type 1 diabetes. METHODS: Thirteen Type 1 patients were included, of whom 10 completed the cross-over study. Ten non-diabetic, matched control subjects were also examined. Body composition was estimated by dual-energy X-ray absorptiometry (DXA) whole-body scanning, diet intake was monitored by 7-day dietary record and insulin sensitivity was measured by the insulin clamp technique at baseline and after each of the diet intervention periods. RESULTS: On an isocaloric low-fat diet, Type 1 diabetic patients significantly reduced the proportion of fat in the total daily energy intake by 12.1% (or -3.6% of total energy) as compared with a conventional diabetes diet (P = 0.039). The daily protein and carbohydrate intake increased (+4.4% of total energy intake, P = 0.0049 and +2.5%, P = 0.34, respectively), while alcohol intake decreased (-3.2% of total energy intake, P = 0.02). There was a significant improvement in insulin sensitivity on the isocaloric, low-fat diet compared with the standard diabetes diet [7.06 +/- 2.16 mg/kg/min (mean +/- sd) vs. 5.52 +/- 2.35 mg/kg/min (P = 0.03)]. However, insulin sensitivity remained 33% lower than in the control subjects (P = 0.021). No significant changes occurred in body weight or body composition. Glycated haemoglobin rose during both diet intervention periods (P = 0.18), with no difference between the two diets. CONCLUSIONS: Change to an isocaloric, low-fat diet in Type 1 diabetic patients during a 3-month period resulted in significant improvement in insulin sensitivity without improvement in glycaemic control. However, insulin sensitivity remained 33% lower than in control subjects.

Absorptiometry, Photon↗

PubMed2003

Food production and wastage in relation to nutritional intake in a general district hospital--wastage is not reduced by training the staff.

BACKGROUND AND AIMS: To assess the amount of food produced in a hospital kitchen and the amount wasted. To assess the amount of food eaten by patients in relation to their energy needs. To assess whether the food production and wastage could be reduced by training members of the staff. METHODS: The study was carried out in a general district hospital in Denmark. The amount of food produced in the hospital kitchen and returned uneaten (wasted) was determined. In a representative sample of patients, the energy expenditure was calculated and in the same patients, the energy and protein intake was determined. Following training of the hospital staff the first part was repeated. RESULTS: On average, 11.1 MJ and 112 g of protein were ordered per patient per day. From these amounts on average 3.1 MJ and 33 g protein were wasted per patient per day. The total average energy expenditure was calculated to be 7.5 MJ per patient per day; however, on average, the daily energy intake was only 4.5 MJ and daily protein intake 46 g per patient. Sixty percent of the patients showed evidence of malnutrition as judged from the hospital notes. However, the staff only drew attention to this in 20% of the cases. Following training of the hospital staff, a new investigation showed no significant changes in the amount of food ordered and wasted. CONCLUSION: Despite a supply of food, which was much higher than the patients' needs, the patients have only approx. 60% of their energy need covered. We suggest a reorganization of nutrition in hospitals, so that this is made the responsibility of specific staff members.

Aged↗

PubMed2002

Use of antibiotics in patients admitted to the hospital due to acute exacerbation of chronic obstructive pulmonary disease (COPD).

BACKGROUND: The purpose of this study was to assess to what extent symptoms and signs of bacterial infection are present and evaluated in patients admitted to the hospital for exacerbation of chronic obstructive pulmonary disease (COPD) in relation to initiation of antibiotic treatment. METHODS: All adult patients (>18 years of age) discharged from a department of internal medicine in Copenhagen in 1997 with a diagnosis of exacerbation of COPD were included in our study and their reports were retrospectively reviewed. Gender, age, number of admissions and length of hospital stay, use of antibiotics and steroids prior to admission, temperature, white blood cell (WBC) count, results of lung auscultation and X-ray examination of the thorax at admittance, and growth of sputum culture and antibiotic treatment in the hospital were all registered. RESULTS: A total of 400 admissions took place. In 104 of them, chest X-ray was compatible with pneumonia, and 99 cases were treated with antibiotics. In 44% of the remaining 296 cases, antibiotics were given. It was found that 25-45% of the patients with very little evidence of infection-i.e. the absence of, or only the presence of, one of the following indicators of infection: fever (temperature>37.5 degrees C), a raised WBC count (>9 billion/l), or crepitation at lung auscultation-were given antibiotics. In cases presenting with two or three of these indicators, 50-75% were given antibiotics. In 85% of the cases, penicillin or a macrolide was the initial antibiotic of choice. The median hospital stay was 6 days for the entire group of patients. CONCLUSION: These data suggest that, in patients with acute exacerbation of COPD, a relatively high number of patients with only weak symptoms or signs of bacterial infection are treated with antibiotics.

Journal Article↗

PubMed2002

Minor long-term changes in weight have beneficial effects on insulin sensitivity and beta-cell function in obese subjects.

AIM: To evaluate the long-term effect of changes in body composition induced by weight loss on insulin sensitivity (SI), non-insulin mediated glucose disposal, glucose effectiveness (SG)and beta-cell function. DESIGN: Glucose metabolism was evaluated before and after participation in a two-year weight loss trial of Orlistat vs. placebo, combined with an energy and fat restricted diet. SUBJECTS: Twelve obese patients (11 women, 1 man), age 45.8 +/- 10.5 years, body weight (BW) 99.7 +/- 13.3 kg, BMI 35.3 +/- 2.8 kg/m(2). MEASUREMENTS: At inclusion and 2 years later an oral glucose tolerance test (OGTT) and a frequently sampled intravenous glucose tolerance test (FSIGT) were performed. Body composition was estimated by a dual-energy X-ray absorptiometry (DXA) whole body scanning. RESULTS: The patients obtained varying changes in BW ranging from a weight loss of 17.8 kg to a weight gain of 6.0 kg. Corresponding changes in fat mass (FM) varied from a 40% reduction to a19% increase. A significant decrease in both fasting (p = 0.038) and 2 h (p = 0.047) blood glucose at OGTT was found. The improvement in insulin sensitivity (SI) estimated by means of Bergmans Minimal Model, was significantly and linearly correlated to change in total FM (r = - 0.83,p = 0.0026). A multiple regression analysis showed that changes in truncal FM was the strongest predictor of change in S(I) explaining 67% of the variation. First phase insulin response (AIRg)remained unchanged whereas insulin disposition index increased significantly (p = 0.044). At inclusion five patients had impaired glucose tolerance of which four, who lost weight, were normalized at the retest 2 years later. CONCLUSION: In obese subjects long-term minimal or moderate changes in weight were found to be linearly associated with changes in insulin sensitivity. In obese subjects with impaired glucose tolerance even a minor weight loss was able to normalize glucose tolerance.

Absorptiometry, Photon↗

PubMed2002

Body composition in adults with Type 1 diabetes at onset and during the first year of insulin therapy.

AIMS: To describe body composition in patients with Type 1 diabetes at diagnosis and during the first year after initiation of insulin therapy. RESEARCH DESIGN AND METHODS: In 10 (eight male and two female) newly onset Type 1 patients, age 31.5 +/- 3.2 years (27-37 years) (sd and range), body mass index (BMI) 20.8 +/- 1.6 (19.2-23.4) kg/m2, body composition was estimated by means of dual-energy X-ray absorptiometry (DXA) whole body scanning supplemented by estimation of total body water (TBW) (isotope dilution technique with 3H2O) at diagnosis and after 1, 3, 6 and 12 months of insulin therapy. RESULTS: During the first year after onset of diabetes body weight (BW) increased 4.3 +/- 2.9 (0.1-8.3) kg (P = 0.0012) distributed as a 13.3% (1.6 kg) increase in total fat mass (FM) and 4.9% (2.5 kg) increase in lean body soft tissue mass (LBM). The self-reported weight loss at onset was 6.3 +/- 2.5 kg (1.5-10.0 kg). Compared with two reference populations the Metropolitan Life Insurance Co. and a healthy age and sex-matched local DXA scanned group the initial body composition data demonstrated BW 6.2 kg below ideal weight and a significant reduction of the FM (25% or -0.87 sd), whereas LBM was within the expected range. CONCLUSIONS: During the first year after onset of Type 1 diabetes the mean increase in BW is 6.5% with a 13.3% increase in FM and a 4.9% increase in LBM. Self-reported data on premorbid BW suggest an approximately 10% reduction in BW at onset of Type 1 diabetes. Compared with a healthy reference population initial body composition data demonstrate a 25% reduction of the FM, whereas only a minor and non-significant reduction in the LBM is encountered. These data indicate that uncontrolled diabetes is rather a fat catabolic state than, as previously believed, a protein catabolic state.

Absorptiometry, Photon↗

PubMed2002

Prognostic value of weight change in chronic obstructive pulmonary disease: results from the Copenhagen City Heart Study.

An association between low body mass index (BMI) and poor prognosis in patients with chronic obstructive pulmonary disease (COPD) has been found in a number of studies. The prevalence and prognostic importance of weight change in unselected subjects with COPD was examined. Subjects with COPD, defined as forced expiratory volume in one second/forced vital capacity < 0.7 in the Copenhagen City Heart Study and who attended two examinations 5 yrs apart, were followed for 14 yrs for COPD-related and all-cause mortality. The proportion of subjects who lost > 1 unit BMI (approximately 3.8 kg) between the two examinations was significantly associated with level of COPD, reaching approximately 30% in subjects with severe COPD. After adjusting for age, smoking habits, baseline BMI and lung function, weight loss was associated with higher mortality in both persons with and without COPD (rate ratio (RR) for weight loss > 3 BMI units 1.71 (95% confidence interval (CI): 1.32-2.23) and 1.63 (95% CI 1.38-1.92), respectively). Weight gain was associated with increased mortality, but not significantly so in subjects with COPD. Risk of COPD-related death increased with weight loss (RR 2.14 (95% CI 1.18-3.89)), but not with weight gain (RR 0.95 (95% CI 0.43-2.08)). In subjects without COPD or with mild-to-moderate COPD, the effect of weight change was the same irrespective of initial weight. In subjects with severe COPD, there was a significant risk ratio modification (p=0.045) between effect of baseline BMI and weight change: in the normal-to-underweight (BMI < 25), best survival was seen in those who gained weight, whereas for the overweight and obese (BMI > or = 25), best survival was seen in stable weight. A high proportion of subjects with chronic obstructive pulmonary disease experienced a significant weight loss, which was associated with increased mortality. The results support further intervention studies that aim at avoiding weight loss in normal-to-underweight chronic obstructive pulmonary disease patients.

Body Weight↗

PubMed2000

Lymphocyte glucocorticoid receptor mRNA correlates negatively to serum leptin in normal weight subjects.

OBJECTIVE: The aim of the present study was to test the hypothesis that glucocorticoid receptor mRNA concentrations decreased with increasing fatness in normal subjects. MEASUREMENTS: Serum leptin concentrations, fat distribution parameters, lymphocyte glucocorticoid (GCR) mRNA, beta2-adrenoceptor mRNA and c-fos mRNA concentrations measured by RT-PCR-HPLC. SUBJECTS: Fifteen healthy non-obese young subjects with a mean body mass index (BMI) of 23. 5+/-0.3 (+/-s.e.m.) kg/m2. RESULTS: Lymphocyte GCR and beta2-adrenoceptor mRNA concentrations averaged 4.2+/-0.2 (+/-s.e.m. ) amol/microg total RNA and 1.4+/-0.1 amol/microg total RNA, respectively. There was a significant negative correlation between serum leptin and lymphocyte GCR mRNA (P<0.01). Serum leptin correlated positively with the waist-hip ratio (P<0.03), whereas lymphocyte GCR mRNA correlated negatively to the waist-hip ratio (P<0.04). Serum cortisol correlated with the weight of the subjects but not the waist-hip ratio or GCR mRNA. CONCLUSIONS: It is suggested that the decrease in lymphocyte GCR mRNA concentration with increasing serum leptin concentrations is a counterregulatory response to an increased body fat content. Further studies are warranted, especially to elucidate the relationship between GCR mRNA in lymphocytes and in fat cells and to clarify the mechanism of the decrease in GCR mRNA.

Adipocytes↗

PubMed1996

Body composition in normal subjects: relation to lipid and glucose variables.

OBJECTIVE: To describe sex- and age-dependent values of total and regional body composition as determined by dual-energy X-ray absorptiometry (DXA) in normal subjects, and furthermore to relate body composition measurements to blood lipids, glucose and insulin concentrations. DESIGN: A cross-sectional study. SUBJECTS: 173 (84 male and 89 female) healthy subjects, BMI < 30 kg/m2. MEASUREMENTS: Body composition parameters including data on total bone mineral content (TBMC), total bone mineral density (TBMD), lean body soft tissue mass (LTM), total and regional fat mass (FM) were estimated in all subjects. In 87 of the subjects fasting blood glucose, S-insulin and lipid profile were measured. RESULTS: The study population was for each sex divided into five decades for which results on body composition and blood lipids are presented. Body weight increased 2 kg per age decade, representing a significant increase in both total FM and relative FM (FM%BW) with age, and in males a central accumulation of FM. LTM decreased significantly in males but not in females, whereas TBMC and TBMD remained constant in males, but decreased in females. A significant correlation between relative FM and S-cholesterol, S-triglyceride, and in males S-insulin was found. CONCLUSION: The present study gives coherent data on bone mineral content, lean body soft tissue mass total and regional fat mass for 173 healthy subjects with a BMI below 30 kg/m2. Total body fat mass increases, and lean mass decreases with age. In males a simultaneous central accumulation of fat mass is observed. The well-known relationship between central obesity and lipids is confirmed even in non-obese subjects.

Absorptiometry, Photon↗

PubMed1995

Validity of dual X-ray absorptiometry scanning for determination of body composition in IDDM patients.

Data on body composition in patients with insulin-dependent diabetes mellitus (IDDM) are scarce. Dual X-ray absorptiometry (DXA) scanning has proved useful for this purpose in other groups of patients. We tested the validity of the DXA scanner for the determination of fat-free mass (FFM) and fat mass in IDDM patients and control subjects, as compared to other reference methods, i.e. total body potassium by 40K whole body counting (TBK), total body water by tritiated water (TBW), bioelectrical impedance analysis (BIA) and 24-h urinary creatinine excretion (Ucrea). A total of 13 healthy controls, 5 males and 8 females, aged 34.2 years +/- SD 10.4, and 11 IDDM patients, 5 males, 6 females, aged 28.1 years +/- 7.3, diabetes duration 4.2 +/- 2.9 (1.0-9.9), were examined. The patients had no long-term diabetic complications and they had normal ophthalmoscopy and urine albumin excretion. The agreement between FFM estimated by DXA and the other methods, expressed as mean difference +/- 2 SD was; for DXA vs. TBK, 0.09 +/- 6.26 and 0.50 +/- 5.26 kg for controls and IDDM patients respectively; DXA vs. TBW, -2.07 +/- 2.56 and -1.07 +/- 4.58 kg; DXA vs. Ucrea, -2.62 +/- 8.02 and 2.00 +/- 10.0 kg; DXA vs. BIA, -7.90 +/- 8.92 and -7.85 +/- 2.32 kg. The results obtained with BIA were significantly different from the other methods for both control subjects and IDDM patients. In conclusion, DXA scanning is a precise and valid method for estimation of fat-free mass in IDDM patients.

Absorptiometry, Photon↗

PubMed1994

The in vivo effect of interleukin-1 beta on urea synthesis is mediated by glucocorticoids in rats.

Interleukin-1 beta has been proposed as one mediator of parts of the catabolic response following surgery. However, it is not known whether such an effect is due to interleukin-1 beta itself or the associated changes in glucocorticoids. The effect of interleukin-1 beta on urea synthesis was investigated in rats given a high (10 micrograms kg-1) and a low dose (0.1 microgram kg-1) of recombinant interleukin-1 beta (NOVO, Denmark) 3 h prior to determination of the rate of urea synthesis in vivo. Urea synthesis increased dose-dependently after the low dose from 4.0 +/- 0.3 (control) to 6.3 +/- 0.3 (P < 0.01), and after the high dose to 7.7 +/- 0.3 mumol (min.100 gBW)-1 (P < 0.01). The blood concentration of amino acids fell during interleukin-1 beta treatment, so the effect on urea synthesis was not due solely to increased proteolysis, but was exerted predominantly in the liver. Pharmacological glucocorticoid receptor blockade (hormone analogue RU486, Roussel-Uclaf, Paris, France) given 1 h prior to the interleukin treatment, completely abolished the interleukin-1 beta induced increases in urea synthesis. The study demonstrates that interleukin-1 beta stimulates urea synthesis in vivo, and that the major part of the effect depends on glucocorticoid action.

Amino Acids↗

PubMed1994

The predictive value of microalbuminuria in IDDM. A five-year follow-up study.

OBJECTIVE: To investigate the predictive value of microalbuminuria and the annual increase of albumin excretion as risk factors for diabetic nephropathy. RESEARCH DESIGN AND METHODS: A 5-year follow-up of patients with microalbuminuria (urinary albumin excretion [UAE] = 30-299 mg/24 h) and matched patients with normoalbuminuria (UAE < 30 mg/24 h). The initial classification was based on one single 24-h urine collection. The annual increase in UAE was calculated by linear regression analysis of log-transformed UAE on time. This study was conducted at the outpatient clinic of the Steno Diabetes Center. The study subjects included 118 insulin-dependent diabetes mellitus (IDDM) patients between 18 and 50 years of age with microalbuminuria and 112 matched control patients with normal UAE with an age at diabetes onset of < 31 years. The main outcome measures were UAE, annual change in UAE rate (percentage per year), and the prevalence of retinopathy. RESULTS: After 5 years, 39 (33%, 24-42 CI [95% confidence interval]) patients with microalbuminuria had normoalbuminuria, 57 (48%, 38-57 CI) still had microalbuminuria, and 22 (19%, 12-27 CI) had developed diabetic nephropathy. Among the 112 patients with normoalbuminuria in 1985, 9 (8%, 4-15 CI) had developed microalbuminuria, and 2 (2%, 0-6 CI) had developed diabetic nephropathy. Of the 79 patients with persistent albuminuria, only 36 (46%, 34-57 CI) were progressors with a rate of progression of > 5%/year. Progressors had significantly higher HbAlc, higher mean blood pressure, and a higher incidence of proliferative retinopathy compared with nonprogressors. Multiple regression analysis only identified mean HbAlc as an independent predictor of the rate of progression. Smoking was significantly more prevalent in patients with persistent albuminuria. CONCLUSIONS: Microalbuminuria is a predictor of progression to diabetic nephropathy; however, not as strong as suggested previously. Calculation of the annual increase in UAE seems to be a more specific method of identifying patients who will develop diabetic nephropathy.

Adult↗

PubMed1993

Effect of glucagon immunoneutralization on the increase in urea synthesis after hysterectomy in rats.

To study the effect of glucagon immunoneutralization on postoperative changes of urea synthesis, hysterectomized rats were given one injection of a specific high titre antibody against pancreatic glucagon 24 h before operation raising the plasma glucagon binding capacity to values 10-20 times higher than the plasma glucagon concentration in control animals. Earlier studies have shown that the spontaneous rate of urea-N synthesis (UNSR) doubles 3 h after operation, and that the Vmax of the process, the capacity of urea-N synthesis (CUNS) is 50% higher than normal values 24 h after operation. Therefore, the effect of glucagon on UNSR and CUNS were investigated 3 and 24 h postoperatively, respectively. Control animals were given non immune rabbit serum. Glucagon immunoneutralization partly normalized the early increase in UNSR 3 h postoperatively (control: 4.7 +/- 0.3, hysterectomy+serum: 6.7 +/- 0.4, hysterectomy+Gluc-Ab: 5.5 +/- 0.4 mumol (min.100 g BW)-1), but had no effect on the increase of CUNS 24 h postoperatively (control: 7.9 +/- 0.3, hysterectomy+serum: 9.5 +/- 0.3, hysterectomy+Gluc-Ab: 9.8 +/- 0.5 mumol (min.100 g BW)-1). This shows that glucagon is important for the early postoperative increase in the efficacy of urea synthesis, whereas the late increase in capacity seems not to depend on hyperglucagonemia.

Animals↗

PubMed1993

No net splanchnic release of glutathione in man during N-acetylcysteine infusion.

Glutathione and amino acid concentrations were measured in arterial and hepatic vein plasma in four healthy volunteers and two patients with cirrhosis. There was no significant splanchnic efflux of glutathione (95% confidence limits, -0.501 to 0.405 mumol/min). After infusion of N-acetylcysteine (NAC) in a high dose (150 mg/kg body weight primer plus 15 mg/(h x kg BW), corresponding to treatment of acetaminophen overdose, there was no change in the splanchnic glutathione efflux (95% confidence limits, -0.531 to 0.375 mumol/min). NAC increased hepatic plasma flow rate from 0.90 +/- 0.531 min-1 to 0.97 +/- 0.11 (mean +/- SEM; p < 0.05). The effects of NAC treatment on plasma amino acids corresponded to an increased load on hepatic metabolic N conversion and transamination among nonessential amino acids. Splanchnic uptake of serine, alanine, cystine, isoleucine, and phenylalanine increased after NAC compatible with stimulated hepatic glutathione synthesis. In contrast to the rat, plasma glutathione in man probably originates mainly from extrahepatic tissues.

Acetylcysteine↗

PubMed1993

Passage of amino acids and glucose across the blood-brain barrier in patients with hepatic encephalopathy.

We repeatedly measured blood-brain barrier passage of phenylalanine, leucine, glucose and GABA in nine patients with hepatic encephalopathy using the intravenous double-indicator technique. Controls were four patients without liver disease and two of the patients who had recovered completely from their hepatic encephalopathy. The corrected cerebral venous output curves were fitted by use of a three-compartment model with four parameters. In the patients with hepatic encephalopathy, the permeability-surface area products for phenylalanine and leucine from the blood to the brain and from the brain interstitial fluid to the intracellular compartment, the unidirectional extraction and the brain amino acid influx were similar in the two groups. The permeability from the brain back to blood for phenylalanine was decreased by 72% in patients with hepatic encephalopathy compared with that in the control group (p < 0.05), whereas no difference was seen for leucine. The permeability from the brain back to the blood for phenylalanine decreased with coma grade and normalized in the two patients who recovered. Correspondingly, the calculated brain interstitial fluid concentration of phenylalanine was increased in the patients with hepatic encephalopathy. The transfer variables for blood-brain barrier passage of glucose were similar in the two groups. The permeability from the blood to the brain for GABA was very low in both the patients with hepatic encephalopathy and the control group. We conclude that in hepatic encephalopathy the permeability from brain to blood for phenylalanine decreases with coma grade. The decrease is caused by an increased interstitial fluid concentration of the amino acid. No evidence was found of general or selective blood-brain barrier disturbance in hepatic encephalopathy.

Adult↗

PubMed1992

Repetitive in vivo treatment with human recombinant interleukin-1 beta modifies beta-cell function in normal rats.

It is unknown whether interleukin-1 exerts a bimodal effect on Beta-cell function in vivo, and whether interleukin-1 has a diabetogenic action in normal animals. We therefore studied: (a) acute effects 2 h after an intraperitoneal bolus injection of 4 micrograms of recombinant human interleukin-1 beta per kg body weight on blood glucose, plasma levels of insulin, glucagon and corticosterone in Wistar Kyoto rats, either untreated or pre-treated with 4 micrograms/kg of interleukin-1 daily for 3 or 5 days; (b) the cumulative effects of repetitive intraperitoneal injections of 4 micrograms/kg interleukin-1 on blood glucose, glucose tolerance, plasma levels of insulin, glucagon and corticosterone, pancreatic insulin content and pancreatic ultrastructure; and (c) blood glucose and plasma concentrations of insulin, glucagon and corticosterone 10 h after the last of five intraperitoneal injections of interleukin-1, at which time point the inhibitory effect of short-term interleukin-1 exposure on insulin secretion reaches its nadir in vitro. A single injection of 4 micrograms/kg of interleukin-1 caused a slight, but significant lowering of blood glucose 2 h after interleukin-1 injection with no significant changes in plasma insulin and in spite of increases in plasma glucagon and corticosterone. A lowering of blood glucose 2 h after interleukin-1 administration was reproduced with 40, but not 0.4 micrograms/kg of interleukin-1, and was also seen in interleukin-1 pre-treated rats. Two hours after the fifth injection of interleukin-1, intraperitoneal glucose tolerance was impaired with elevated plasma insulin and corticosterone levels and increased pancreatic insulin content, indicating a state of insulin resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Effects of epinephrine on urea synthesis in vivo in rats.

Three hours after hysterectomy the rate of urea synthesis doubles in rats. At the same time the increase in catecholamines is at a maximum, suggesting that catecholamines might be of regulatory importance. The effect of exogenous epinephrine on the rate of urea synthesis was studied in rats receiving epinephrine at rates of 2 and 20 micrograms/kg/h. The low dose increased plasma concentration of catecholamines two-fold over control values (p less than 0.01), comparable with the increase seen after surgery, and the high dose of epinephrine increased the concentration five-fold. The high dose increased the rate of urea synthesis by 30% (p less than 0.05), whereas the low dose had no effect. Following a high dose of epinephrine, alanine decreased from 358 +/- 29 to 254 +/- 17 mmol/l (p less than 0.05), indicating that the increase in urea synthesis was due to an effect on the liver rather than on extra-hepatic tissues, in that more aminonitrogen was eliminated from plasma than released into it. In conclusion, epinephrine in physiological concentrations cannot by itself account for the increase of urea synthesis seen in vivo after surgery.

Amino Acids↗

PubMed1992

Stimulatory effect of epidermal growth factor on liver regeneration after partial hepatectomy in rats.

The effect of epidermal growth factor (EGF) on liver regeneration was investigated in rats subjected to partial hepatectomy. In a dose-response study EGF in doses of 6 and 24 nmol/kg x day increased liver regeneration after treatment for 48 h compared with controls, whereas a dose of 48 nmol/kg x day had no effect. In a subsequent study EGF, 6 nmol/kg x day, accelerated liver regeneration significantly after 36, 48, and 72 h of treatment. A possible influence of EGF on other hepatotrophic factors was investigated. No changes in the concentration of gastrin, insulin, or glucagon was found in portal venous blood. This study has shown that EGF in small doses can stimulate liver regeneration, whereas higher doses are ineffective. The study suggests that EGF should be regarded as a hepatotrophic factor.

Animals↗

PubMed1992

Hormonal and neural blockade prevents the postoperative increase in amino acid clearance and urea synthesis.

The combined effect of continuous blockade of glucagon and cortisol by somatostatin and etomidate and thoracic epidural analgesia on hepatic conversion of amino nitrogen was studied in eight patients who underwent elective cholecystectomy on day 1 after operation and was compared with 16 patients who underwent operation without blockade. Surgery increased the plasma clearance of total alpha-amino nitrogen from 5.2 +/- 0.3 to 6.6 +/- 0.3 ml/sec (mean +/- sem; p less than 0.05). This increase was due to increased elimination by the liver, because the hepatic effectiveness for amino nitrogen conversion measured by the functional hepatic nitrogen clearance increased from 9 +/- 2 to 16 +/- 4 ml/sec (p less than 0.05). In contrast, during the combined neural and hormonal blockade, surgery decreased the plasma clearance of amino nitrogen from 5.3 +/- 0.3 to 3.9 +/- 0.3 ml/sec (p less than 0.05), and the blockade prevented the postoperative increase in functional hepatic nitrogen clearance. The results suggest that glucagon, cortisol, and afferent neural reflexes are mediators of the hepatic contribution to catabolism after operation.

3-Hydroxybutyric Acid↗