The lipase activity of sheep pancreatic juice.

Abstract

Sheep pancreatic juice contains a powerful lipolytic enzyme which under optimum conditions can release 47·9 ± 2·0 µ‐equiv fatty acid/mg freeze dried pancreatic juice/min from a triglyceride/bile salt emulsion. The properties of this enzyme are consistent with those of lipase (EC3.1.1.3). The pH optimum of the lipase is 7·5 and negligible activity is found below pH5, suggesting that little hydrolysis of triglyceride can occur in the duodenum and upper jejunum of the sheep (pH 2·5‐5·0). The lipase is sensitive to acid in the range pH 2·5‐3·5. Pre‐incubation at pH 3·0 resulted in a 75% loss of lipase activity and at pH 2·5 practically all lipase activity was destroyed. The addition of duodenal secretions, bile and pancreatic juice increased the pH of abomasal digesta by 0·1, 0·3 and 0·1 units respectively, which was sufficient to protect most of the lipase from acid inactivation by abomasal digesta (pH 2·5).