An inhibitor of a-amylase was isolated and purified from an extract of white kidney beans (Phaseolus vulgaris). The acute oral administration of the inhibitor (50 mg/kg body weight) to adult Wistar rats together with a starch load (2 g/kg body weight suspended in NaCl (9 g/l)) reduced the increase in glycaemia over the basal value (NaCl, 222 (SEM 49); inhibitor, 145 (SEM 16) mmol/l £ 180 min; P, 0·05) without modifying the insulin response. On administering the inhibitor orally (50 mg/kg body weight dissolved in NaCl (9 g/l)) for 21 d to rats fed on a standard diet, a decline was observed in the glycaemia values on day 0 (NaCl, 5·53 (SEM 0·12); inhibitor, 5·25 (SEM 0·16) mmol/l) relative to those obtained on days 10 (NaCl, 5·00 (SEM 0·14); inhibitor, 4·60 (SEM 0·08) mmol/l; P,0·05) and 21 (NaCl, 5·22 (SEM 0·22); inhibitor, 4·50 (SEM 0·12) mmol/l; P,0·01) of treatment, without modifying the plasma concentration of insulin. There was found to be a significant anorexigenic action of the inhibitor; there was reduced food intake (NaCl, 23·07 (SEM 0·31); inhibitor, 19·50 (SEM 0·49) g/ d; P,0·01), a reduced weight gain (NaCl, 52 (SEM 3); inhibitor, 2 1·33 (SEM 8·9) g/21 d; P, 0·01), as well as changes in the activity of some intestinal enzymes such as maltase (NaCl, 87 (SEM 7); inhibitor, 127 (SEM 11) U/g proteins; P,0·05). The present study has shown, for the first time, that the prolonged administration of an a-amylase inhibitor reduces blood glucose levels and body-weight gain in Wistar rats.a-Amylase inhibitor: Glycaemia: Weight: Food intake: Disaccharidases

No abstract

A model of hypertriglyceridaemia in rats is described, which was used to investigate the hypolipidaemic effect of an intraperitoneal (i./p.) administration of a Ficus carica leaf decoction. Hypertriglyceridaemia was induced in rats following the protocol: a fasting period of 22 h, 2 h of oral (p.o.) administration of 20% emulsion of longchain triglycerides (LCT emulsion), both repeated once. The plasma triglyceride and total cholesterol levels obtained 2 h after the protocol were 5.7 ± 2.5 mmol/L (p < 0.0001 vs basal levels) and 1.7 ± 0.3 mmol/L, respectively, n = 10. The new model was used to test the hypotriglyceridaemic effect of a single dose of Ficus carica (fig tree) leaf decoction administered i./p. (50 g dry wt/kg body wt). After the i.p. injection of serum saline (control group, n = 10) or Ficus carica extract (group A, n = 10), plasma triglyceride levels in the control group and group A were 5.9 ± 2.9 mmol/L and 5.5 ± 2.9 mmol/L just after the LCT emulsion protocol; 4.7 ± 2.7 mmol/L and 0.9 ± 0.4 mmol/L, p < 0.005, 60 min after the LCT protocol; and 3.6 ± 2.9 mmol/L and 1.0 ± 0.4 mmol/L, p < 0.05, 90 min after the LCT protocol. The plasma total cholesterol levels, which were not modified in our experimental model, showed no significant differences in relation to baseline levels in the presence or absence of Ficus carica treatment either. The clearly positive results suggest the presence in the fig leaf decoction of a compound or compounds that influence lipid catabolism. Copyright © 1999 John Wiley & Sons, Ltd.

SummaryIndividual housing has been reported to modify animal behaviour. The present study compares the plasma levels of glucose, triglycerides and total cholesterol, weight, and food and water intake in two groups of female rats. Group A: 10 rats who remained grouped in two cages for 21 days; and Group B: 10 rats housed in two cages for 7 days, then isolated in individual cages from day 8 to day 15, and finally grouped together again for the last 7 days of the study.The results showed that the plasma values of glucose declined (P

Objective-To reports changes in plasma levels in professional racing cyclists. Methods-Plasma levels of the intracellular enzymes aspartate aminotransferase, alanine aminotransferase, y glutamyl transpeptidase, lactate dehydrogenase, and alkaline phosphatase were measured resting and after exercise in professional cyclists participating in two road races: Vuelta Cicista a Valencia (800 km, beginning of the cyclist season), and the top rank race Vuelta a Espafia (2700 km, at the end of cyclist season). Results-A significant increase in plasma aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase was observed at the end of the race over the corresponding paired start values (P < 0.05). The increase in plasma lactate dehydrogenase after the race was only statistically significant (P < 0-05) in the Vuelta a Espafia. The longer the duration of the cycle tour race, the greater were the increases in aspartate aminotransferase and alanine aminotransferase levels. The high levels returned to their start values during the overnight resting period. Conclusions-The presence of these enzymes in the blood is probably due to mechanically damaged muscle cells leaking their contents into the interstitial fluid. (BrJt Sports Med 1996;30:122-124)

No abstract

The isolated perfused rat pancreas was utilized to investigate the effect of oleic acid on insulin secretion. In the absence of glucose, a continuous infusion of oleic acid (1500 micromol/l) induced a biphasic insulin release. This effect was reduced at low extracellular calcium concentration. In the presence of oleic acid 1500 micromol/l, the insulin response to 10 mmol/l arginine occurred earlier, the total amount of insulin released in response to the amino acid being unchanged. Such an effect was not obtained when oleic acid in the medium was 750 micromol/l, but it was observed in the presence of oleic acid 1500 micromol/l when the concentration of albumin in the perfusate was increased from 2 g/100 ml to 4 g/100 ml. The insulin response to a continuous infusion of glucose (4.4 mmol/l and 16.7 mmol/l) was potentiated by the presence of oleic acid 1500 micromol/l in the perfusate. No modification of the biphasic pattern of insulin response to glucose 16.7 mmol/l was observed. These results demonstrate that high concentrations of oleic acid stimulate insulin release from the isolated perfused rat pancreas and modulate the insulin response to arginine or glucose.

To investigate the hypoglycaemic activity of Ficus carica leaf aqueous extract, a decoction was administred to rats in lieu of drinking water for three weeks. The groups were: untreated non-diabetic (n = 13), untreated diabetic (n = 13), treated non-diabetic (n =13) and treated diabetic (n = 13) animals. The extract decreased (p < 0.025) plasma glucose in diabetic (27.9 ± 4.5 mmol/L to 19.6 ± 9.9 mmol/L) while not in normal rats. Plasma insulin levels were decreased by treatment (p < 0.05) in non-diabetic rats from 4.9± 1.6 ng/mL to 3.3 ± 1.2 ng/mL. Glucose uptake (µmol/min) by rat hindquarters perfused was: 5.9 ± 2.2 (untreated non-diabetic rats), 4.8 ± 2.3 (treated non-diabetic rats, p < 0.05 vs. untreated non-diabetic rats), 2.0 ± 2.0 (untreated diabetic rats, p < 0.01 vs. untreated non-diabetic rats) and 4.1 ± 3.6 (treated diabetic rats) in absence of insulin; 7.0 ± 1.7 (untreated non-diabetic rats), 8.3 ± 0.8 (treated non-diabetic rats, p < 0.05 vs. untreated non-diabetic rats), 5.0 ± 1.6 (untreated diabetic rats, p < 0.05 vs. untreated non-diabetic rats) and 6.4 ± 2.4 (treated diabetic rats) in presence of insulin. Lactate released was lower in untreated diabetic vs. untreated non-diabetic rats. Thus, Ficus carica extract showed a clear hypoglycaemic effect in diabetic rats. Such an effect cannot be mediated by an enhanced insulin secretion, so an as yet undefined insulin-like peripheral effect, may be suggested.