SH-groups on the surface of pancreas cells involved in secretin stimulation and glucose-mediated secretion

Abstract

A large derivative of p- chloromercuribenzoic acid (PCMB-Dextran T 10, mol. wt approx. 10000) was perfused through an isolated preparation of cat pancreas. It was shown that PCMB-Dextran T 10 inhibited pancreatic fluid and electrolyte secretion by 47%. When glucose in the perfusate was replaced by other substrates, PCMB-Dextran T 10 caused an inhibition of only 26%. Replacement of secretin by dibutyryl cyclic AMP and theophylline led to an inhibition of 15%. When secretin as well as glucose was replaced by its substitutes, no inhibition of secretion could be achieved with PCMB-Dextran T 10. Considering the large molecular size of this mercurial compound it can be concuded that SH-groups on the surface of the pancreatic cells are essential both for the action of secretin and for the glucose-mediated secretion.