Insulin and glucagon impairments in relation with islet cells morphological modifications following long term pancreatic duct ligation in the rabbit--a model of non-insulin-dependent diabetes.

Plasma levels of glucose, insulin and glucagon were measured at various time intervals after pancreatic duct ligation (PDL) in rabbits. Two hyperglycemic periods were observed: one between 15-90 days (peak at 30 days of 15.1 +/- 1.

Myocardial prostacyclin and thromboxane A2 synthetase activities during ischemia and reperfusion in isolated rabbit heart.

The aim of the study was to determine the prostacyclin (PGI2) and thromboxane A2 (TXA2) synthetase activities of myocardial tissue and their variation during ischemia and reperfusion. Regional ischemia was induced by 10 min occlusion of the left anterior descending coronary artery in isolated Langendorff rabbit hearts. Biosynthesis of PGI2 and TXA2 were carried out by using arachidonic acid as substrate and left ventricle microsomes (LVM) from ischemic and non-ischemic areas as sources of PGI2 and TXA2 synthetase.

Study of the PG E2 synthetase activity of different regions of dog and rabbit hearts.

Prostaglandin E2 synthetase activity of the microsomal fraction from different parts of dog and rabbit heart was tested with 3H-arachidonic acid as substrate. PG E2 synthesized was separated and purified by TLC and determined by the radiometric method or by bioassay. In the experimental conditions adopted, it was shown that the heart tissue is endowed with an enzyme system capable of synthesizing PG E2 but this PG E2 synthetase activity is not uniformly distributed in the different parts of the heart.

Cardiovascular activity of a deproteinized blood extract.

The cardiovascular effects of the deproteinized blood extract were investigated in anaesthetized dogs: respiration, general metabolism and systemic haemodynamics were tested and the changes in these parameters after the administration of the drug were studied. At 2 ml kg-1 i.v.

[Activity of rabbit heart on thromboxane synthetase].

The soluble and microsomal fractions of Rabbit myocardium are not able to induce the synthesis of thromboxanes. On the contrary, they inhibit the thromboxane synthetase of various sources. The chemical structure of the active constituent responsible for this activity is not yet known: it is probably neither of an enzymatic nature, nor a protein of high molecular weight.