Effect of sodium succinate on metabolic and morphological changes in acute cooling

The effect of sodium succinate preinjection (16 mg/kg) on the resistance of mice to acute low-temperature exposure was studied. The measurements were taken of the changes in blood glucose concentration, of the content in the heart of macroergic compounds and glycogen, and of succinate dehydrogenase activity. Cardiomyocytes were studied by electron microscopy. The data indicate that greater preservation of macroergic compounds and stabilization of the ultrastructure of myocardial mitochondria play a role in the mechanism by which the animals' resistance to intense cooling is increased after sodium succinate injection.     

An explanation of gastric hypersecretion in the pylorus-ligated rat

The hypersecretion of gastric acid in the pylorus-ligated rat has been shown to be of vagal origin. The present series of experiments were performed to identify the stimulus. The pyloric sphincter was ligated in a series of Sprague Dawley rats. Along with pylorus ligation, various other surgical manipulations were performed. Intestinal obstruction by ligation approximately 20 cm aboral to the cecum reduced unstimulated gastric secretion in the pylorus-ligated rat. However, perfusion of the lower small intestine with bicarbonate (143 mEq/L) stimulated secretion. Perfusion with either saline or deoxycholic acid (20 mEq/L) did not alter secretion. This supports a role for bicarbonate in the hypersecretion of gastric acid in the pylorus-ligated rat. The reflex appears to involve the myenteric plexus, since section of the pylorus seemed to attenuate gastric secretion. Plasma from animals with pylorus ligation, either alone or with intestinal ligation, equally inhibited gastric secretion. This suggests that while some factor inhibiting gastric secretion may be present, it appears to be unrelated to pylorus ligation.     

Effect of sodium succinate on several carbohydrate metabolism indices of ischemic myocardium]

The influence of sodium succinate on the content of lactic, pyruvic acids and glucose in the venous blood flowing from the ischemic zone of the myocardium was studied in dogs with ligated coronary artery. The intracoronary injection of the preparation in doses of 2 and 10 mg/kg diminished the content of blood lactic acid flowing from the ischemic zone; a dose of 10 mg/kg decreased the consumption of glucose by the ischemic myocardium. Sodium succinate (100 mg/kg) intravenously reduced the content of the lactic acid significantly and inhibited the glucose consumption by the ischemic myocardium, with its increase in the arterial blood. A fall of lactacidemia can be connected with the activation of Krebs cycle and an increase of oxygen utilization by the ischemic myocardium.     

Effect of insulin administration on water drinking in children

The effect of insulin administration on water intake, was studied in children submitted to standard protocols for stimulation of secretion of hypophyseal hormones by i.v. treatment with several different drugs: insulin, insulin plus TRH and LH-RH; and propranolol, clonidine or LH-RH. Drinking was measured from 0 to 90 min after drug administration; from blood samples taken at 60 min for hypophyseal hormones analysis, microhaematocrit values were measured, as well as plasma renin activity (PRA) and glycaemia. Water intake was significantly higher in both groups of patients receiving insulin than in the control group (no insulin). Haematocrit values did not change after 60 min. There was a significant correlation of glycaemia of individuals from all three groups and water intake at 60 min. PRA was significantly higher in insulin treated individuals.