Metabolic Fate of the Glucose Taken up by the Intestine During Induced Hyperglycaemia in Dogs.

Available data showed that the intestine increases it glucose uptake in response to hyperglycemia induced by anycause. However, what the intestine does with the glucose is not known. This study investigated the metabolic fate of theglucose taken up by the intestine during hyperglycaemia in dogs. Experiments were carried out on fasted, male, anaesthetizedmongrel dogs divided into 4 groups. The control (group 1, n=5) received normal saline (0.2 ml/kg) while groups 2-4(subdivided into two as low or high dose, n=5 each) received adrenaline (1 µg/kg or 5 µg/kg), glucagon (3 ng/kg or 8 ng/kg)and glucose (10 mg/kg/min or 20 mg/kg/min). Through a midline laparatomy, the upper jejunum was cannulated for IntestinalBlood Flow (IBF) measurement. Blood glucose and lactate levels were determined using glucose oxidase and lactatedehydrogenase methods, respectively. Intestinal Glucose/Lactate Uptake (IGU/ILU) was calculated as the product of IBFand arterio-venous glucose /lactate difference [(A-V) glucose/lactate]. Jejunal tissue samples were obtained for the determinationof Glycogen Content (GC) and activities of Glycogen Synthase (GS), Glycogen Phosphorylase 'a' (GPa), hexokinase andglucose-6-phosphatase. Anthrone method was used to determine GC while activities of GS, GPa, hexokinase and glucose-6-phosphatase were determined spectrophotometrically. Data were subjected to descriptive statistics and analyzed usingstudent's t-test and ANOVA at α0.05. Arterial and venous blood glucose and lactate were increased by adrenaline, glucagonand glucose. Venous lactate was higher than arterial lactate in all groups. Intestinal blood flow, (A-V) glucose and (A-V)lactate were increased in all the experimental groups. Intestinal glucose uptake increased by 624% (adrenaline), 705%(glucagon) and 589% (glucose) while intestinal lactate release increased by 422%, 459% and 272% respectively. IntestinalGC increased from 138.72 ± 4.58 mg/100 g to 167.17 ± 4.20 mg/100 g (adrenaline), 229.21 ± 6.25 mg/100 g (glucagon) and165.17 ± 4.20 mg/100 g (glucose). Adrenaline and glucose had no effect on GS activity but it was increased by glucagon;GPa was decreased while hexokinase activity was increased by adrenaline, glucagon, and glucose. Glucose-6-phosphataseactivity was not affected by adrenaline and glucagon but decreased by glucose. The intestine modulates blood glucose levelsthrough lactate formation, glycogen formation and most probably conversion of lactate to glucose through gluconeogenesis.

Differential effects of total and partial sleep deprivation on salivary factors in Wistar rats.

OBJECTIVE: Aim of this study was to investigate the effects of sleep deprivation on salivary factors in rats. DESIGN: Animals were randomly assigned into three groups of 6 animals each as control, total sleep deprivation (TSD) and partial sleep deprivation (PSD) groups. The multiple platform method was used to induce partial and total sleep deprivation for 7days. On the 8th day, stimulated saliva samples were collected for the analysis of salivary lag time, flow rate, salivary amylase activity, immunoglobulin A secretion rate and corticosterone levels using ELISA and standard kinetic enzyme assay. Data were analyzed using ANOVA with Dunnett T3 post hoc tests. RESULTS: Salivary flow rate reduced significantly in the TSD group compared with the PSD group as well as the control group (p=0.01). The secretion rate of salivary IgA was significantly reduced in the TSD group compared with the control group (p=0.04). Salivary amylase activity was significantly elevated in the TSD group compared with the PSD group as well as control group (p<0.001). However, there were no significant changes in the salivary lag time and levels of corticosterone among the groups. CONCLUSIONS: These findings suggest that total sleep deprivation is associated with reduced salivary flow rate and secretion rate of IgA as well as elevated levels of salivary amylase activity in rats. However, sleep recovery of four hours in the PSD group produced ameliorative effects on the impaired functions of salivary glands.

Aging affects morphology but not stimulated secretion of saliva in rats.

BACKGROUND: The role of aging on the salivary gland function still remains controversial and inconclusive. This study was undertaken to determine the effects of aging on the morphology and secretion of salivary glands using male Wistar rats. METHOD: There were three age groups; group A (3 months old; n = 8), group B (6 months old; n = 8), and group C (9 months old; n = 8). Body weights, salivary gland weights, salivary flow rates, pH and salivary levels of sodium, potassium, calcium, chloride, bicarbonate, phosphate and total protein were measured and compared. Hematoxylin-eosin stained histological slides of the salivary glands were assessed for morphological changes. RESULTS: Body weights increased with age while mean parotid gland weight was significantly higher in group B than in groups A and C. Mean salivary flow rate was significantly higher in group B and C than in group A, and mean salivary pH was significantly higher in group B and C than group A. Analysis of salivary electrolytes and total protein showed that mean levels of sodium, potassium and bicarbonate increased with age significantly while mean levels of calcium, chloride, phosphate and total protein did not show significant change among the groups. CONCLUSION: These findings showed that varying changes were observed in the morphology of salivary glands of aging rats without impaired function.

Gastro-protective effect of methanol extract of Ficus asperifolia bark on indomethacin-induced gastric ulcer in rats.

The gastro-protective and antioxidant effects of methanol extract of Ficus asperifolia bark on indomethacin induced gastric ulcer were investigated in male rats. Thirty two male rats divided into 4 equal groups and were treated as follows: group1 (control), 0.5ml of 5% tween 80 (vehicle for the extract), groups 2 and 3, 100 and 500mg/kg of Ficus asperifolia extract respectively and group 4, cimetidine (100mg/kg). After two weeks of daily oral administration of vehicle, extract or cimetidine, gastric ulcer was induced in all rats with indomethacin (40 mg/kg, p.o). Gastric juice pH, gastric acid concentration, gastric ulcer score, percentage gastric ulcer inhibition, activity levels of superoxide dismutase (SOD), catalase and malondiadehyde (MDA) were determined. Ficus asperifolia extract significantly increased gastric pH (p<0.05) but decreased (p<0.01) gastric acid secretion in dose dependent manner when compared with the control. Inhibition of gastric ulcer in extract and cimetidine treated rats was similar. Activities of SOD and catalase were significantly increased (p<0.05) while MDA was significantly decreased (p< 0.05) in extract treated rats when compared with the control. The results suggest that Ficus asperifolia possesses gastro-protective and antioxidant properties against gastric ulcer induced by indomethacin.