Post-prandial lipase, pepsin and acid secretion of a Heidenhain pouch in the rabbit.

The kinetics of the gastric secretion of lipase, pepsin and acid were studied after a meal in Heidenhain-pouch rabbits. After a 24-h fast, feeding immediately stimulated (< 15 min) lipase (x 4.1) and later on pepsin (x 1.8) output which reached respectively 16 and 47% of the output observed after pentagastrin stimulation (64 micrograms.kg-1.h-1 for 1 h), and which were significantly correlated. Lipase concentration was enhanced earlier and to a greater degree (x 7.3) than pepsin concentration (x 2.5). No stimulation of high basal acid secretion occurred. It was concluded that: 1) gastric lipase secretion is stimulated by feeding in the rabbit; 2) pepsin secretion is stimulated by feeding. The modalities of the secretion of lipase and pepsin are compatible with the existence of distinct secretory cells; 3) acid secretion is not stimulated by feeding. The decrease in acid secretion during the post-prandial phase favors a physiological role for lipase which is altered by low pH. The absence of acid stimulation by feeding in the rabbit, in contrast to other species, requires additional studies on the release of gastrointestinal hormones, namely gastrin, cholecystokinin and somatostatin.