Pancreatic endocrine function in cirrhotic rats

Abstract

Pancreatic endocrine function in liver cirrhosis was examined in rats both in vivo and in vitro. Experimental liver cirrhosis was induced by subcutaneous injections of 50% carbon tetrachloride in a dose of 2 mL/kg body weight twice a week for 16 weeks. Control rats received a similar dose of olive oil during the same period. In cirrhotic rats, immunoreactive insulin contents in the pancreas were significantly lower, whereas immunoreactive glucagon contents were about threefold higher than those of control rats. In the first part of this study, insulin and glucagon concentrations in both jugular and portal venous blood at basal conditions and after oral glucose loading were simultaneously determined in vivo. Peripheral insulin levels, both before and after glucose loading, were higher, whereas portal insulin concentrations were lower in cirrhotic rats than in the control rats. In contrast, glucagon levels in both the peripheral and portal veins were significantly higher in cirrhotic rats than in control rats. In the second part, isolated perfused pancreata were prepared from cirrhotic and control rats to further characterize the endocrine function of cirrhotic rat pancreas. Insulin secretion in response to 16.7 mmol/L glucose and 100 pmol/L cholecystokinin-octapeptide both were 40% lower in cirrhotic rats than in controls. In contrast, there was no significant difference in arginine-stimulated insulin release between the two groups. However, glucagon secretion in response to 20 mmol/L arginine was 40% higher in cirrhotic rats. If sensitivity is defined as the hormone release proportional to the pancreatic contents, then A and B cells in the cirrhotic rats had normal sensitivity to both glucose and cholecystokinin-octapeptide.(ABSTRACT TRUNCATED AT 250 WORDS)