Effect of temperature and anaesthetics on gastric acid secretion in isolated rat stomachs

The effect of temperature and anaesthetic agents, like urethane, chloralose and pentobarbitone, on basal and stimulated gastric acid secretion was investigated in isolated perfused and isolated everted rat stomachs. Histamine increased acid secretion when injected into the cold (20°C) 'nutrient' solution bathing the mucosa in the everted stomach while the effect was not seen when injected into the warm (37°C) 'nutrient' solution. In contrast histamine did not stimulate acid secretion in the isolated perfused rat stomachs when added to the perfusate solution (37°C). In warm conditions (37°C) urethane, 5 mg/ml, and pentobarbitone, 250 g/ml had no effect on secretory parameters while chloralose, 5 mg/ml, inhibited basal secretion and had no effect on stimulated secretions. Differences exist between anaesthetics in relation to their antisecretory actions. The isolated everted rat stomach is a useful technique in studying gastric secretory and inhibitory mechanisms at different temperatures although it is not entirely physiological. It has an advantage that indirect effects like vascular, neural and hormonal, and drug metabolism and excretions are minimised.