[The effects of an oral calcium overload on the rat exocrine pancreas]

The possible induction of functional or morphologic changes in the exocrine pancreas of the rat by oral calcium overload was studied to determine the possible relationship to predisposition of acute pancreatitis over the acinar theory.

Oral chloride calcium (0.45 and 0.25 g/kg body weight/day) plus cholelecalciferol (300,000 UI/kg i.m.) were administered to male Wistar rats over 1 to 3 months. Half of each group, including a control were submitted to cholinergic stimulation with carbamylcholin. After anesthesia, blood and pancreatic tissue and duodenal fluid were extracted for enzymatic and ultrastructural studies.

In the rats treated with high doses of calcium for 1 month greater tissue concentrations of amylase, lipase and trypsin were observed. Moreover, there was a greater trend to the presence of dilated ergastoplasm. In the rats treated with high doses over 3 months a lower enzyme concentration was observed in the animals not stimulated that in the control group. On stimulation with carbamylcholin, higher concentrations of enzymes were observed in tissue than in those not stimulated. This was accompanied by a lower number of exocytosis in this experimental group that in the control.

A possible increase in the calcium concentration in the acinar cell may lead to dysfunction in the secretory mechanisms favoring the intracellular accumulation of digestive enzymes, predisposing intracellular activation, in the context of the acinar or lysosomal hypothesis of acute pancreatitis.