[Participation of the gastrointestinal tract in regulating the processes of insulin liberation by the pancreas].

Three elevations of the insulin concentration in the blood of the v. pancreaticoduodenalis and v. portae were found in dogs fed with food containing mainly proteins, fat or carbohydrates.

[Insulin secretion in dogs with experimental pancreatitis to the intrapancreatic administration of glucose].

Early immunoreactive insulin and glucose alterations were studied in the pancreatoduodenal vein of dogs with experimental hepatitis after rapid glucose injection into the pancreatic artery. The blood was collected from the pancreatoduodenal vein every 10 s. In the early period of insulin release the stimulant effect of glucose on insulin secretion was less pronounced in animals with experimental hepatitis as compared with control.

[Dynamics of insulin secretion in dogs with alloxan diabetes].

It was shown that hypoinsulinemia in the superior pancratico-duodenal vein and inhibition of the first phase of insulin secretion by the pancreas characteristic of alloxan diabetes of different severity was absent in the femoral vein. The data obtained in the insulin and glucose concentration study in the superior pancreatico-duodenal vein stressed the leading role of the pancreatic factor in the pathogenesis of alloxan diabetes in dogs. Analysis of these parameters in the peripheral femoral vein failed to reflect this statement adequately.

[Insulin concentration in plasma from the femoral, hepatic and pancreatico-duodenal veins of dogs under standard conditions and in corisone glucose tolerance tests].

In comparing the results of glucose tolerance tests conducted against the background of cortisone action and without it the former one proved to have advantages over the latter one in studying the incretory function of the pancreas. A biphasic character of insulin secretion in glucose loading was revealed with the aid of this test. Secretion of insulin by the pancreas was better reflected by the dynamics of insulin content in the blood of the pancreatic-duodenal vein that by the dynamics of its content in the blood of the peripheral veins.

[Activity of NAD- and NADP-dependent malate dehydrogenase isoenzymes in the myocardium of rabbits with alloxan diabetes].

Isoenzymes NAD-and NaDP MDH were detected in the cardiac muscle of rabbits by disc electrophoresis in polyacrylamide gel. Alloxan diabetes proved to be accompanied by a significant reduction in the activity of mitochondrial NADP MDH (in the reaction of malic decarboxylation) and its increase in cytozol. The activity of NAD-MDH (in the reaction of oxyacetate reduction) was also decreased in various isoenzymes in the myocardium (particularly in the mitochondria) in diabetes.

[Lactate dehydrogenase and malate dehydrogenase isoenzymes in the myocardium and liver of rabbits with thyrotoxicosis].

Isoenzyme spectra of lactate and malate dehydrogenases were studied by means of polyacrylamide gel disc electrophoresis in heart muscle and liver tissue of rabbits with thyreoidin toxicosis. Under conditions of thyreotoxicosis in liver tissue content of isoenzymes LDH4 and LDH5, which slowly moved to anode, was decreased; in heart muscle content of LDH2-LDH5 was also decreased. In liver tissue the relative predominance of LDH1-LDH2 was observed, in heart muscle of LDH1.