POSTPRANDIAL 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, f eeding immediately stimulated (< 15 min) lipase (x 4.1) and later on p epsin (x 1.8) output which reached respectively 16 and 47% of the outp ut observed after pentagastrin stimulation (64 mug-kg-1.h-1 for 1 h), and which were significantly correlated. Lipase concentration was enha nced 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 modal ities of the secretion of lipase and pepsin are compatible with the ex istence of distinct secretory cells; 3) acid secretion is not stimulat ed 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 contr ast to other species, requires additional studies on the release of ga strointestinal hormones, namely gastrin, cholecystokinin and somatosta tin.