Purification of plasma membranes from rat pancreas: a rapid method.

Introduction. The role of adenylate cy-clase and cyclic nucleotides in the secretory processes of the exocrine pancreas is not well defined. It has been reported that adenylate cyclase activity can be increased by secretin and, to a lesser degree, by pancreo-zymin (12). Kempen et al. (3) found that phospholipid addition increased the sensitivity of adenylate cyclase to pancreozymin. Moreover, some authors have reported that dibutyryl cAMP induces enzyme secretion (456), while others found no effect (78).In spite of these controversial results, it is accepted that cyclic AMP could be involved as an intracellular mediator for hydralatic secretion (910), while cyclic GMP might be an intracellular messenger for enzyme secretion (1112).Purification of plasma membranes is a prerequisite for the study of molecular mechanisms underlying the hormonal and cholinergic responses of the exocrine pancreas. We describe here a rapid and simple method for the isolation of plasma membranes from the rat pancreas.Materials a...