Retrials of Ultracytochemical Demonstrations of Tween Lipase in Pancreas

Abstract

Histochemical method of Tween lipase was studied on pancreatic tissues of male rats by means of reaction medium containing various amounts of glycerin, dimethylsulfoxide (DMSO)or triton X-100, at pH 6-8, for 3-40 hours. The medium (5% Tween 80; 1.0 ml,0.2M Tris HC1 buffer; 2.5m1,10% calcium chloride; 1. Oml, ad Aq. dist.; 25. Oml) containing 5%DMSO and 0.25% sodium taurocholate, final pH 6.2, was followed by the best demonstrati on of lipase activity. Holczinger's copper-rubeanic acid technique was also available for the visualization
Small blocks of rat pancreatic tissues were fixed in buffered 2.5% glutaraldehyde for 3 hours, washed in cacodylate buffer overnight, cut 40μ by Vibratom. These tissue slices were incubated in above-mentioned medium at 37°C for 5 hours, rinsed in cacodylate buffer, immersed in 0.1% lead nitrate for 15 minutes, washed thoroughly in cacodylate buffer, post-fixed in osmium buffer, dehydrated in cold ethanols, and embedded in epon. The reaction products for lipase activity were observed in the cisternae of ER and Golgi apparatus, around the zymogen granules and lysosomes, and within the secretory canaliculi of pancreatic acini and the pancreatic ductules.