Specific Hormonal Regulation, by Food, of the Pancreas Enzymatic (Amylase and Trypsin) Secretions

Abstract

The duodenal mucosa has long been shown to be the source of hormones which participate in the control of exocrine pancreatic secretion. However, little is known of the stimulation of these hormones by food substrates. In order to study this regulation, the following experiment has been carried out: an oral glucose load or a lactalbumin-hydrolysate load was given to a first series of rats: the duodenal mucosa was removed at various times after the oral load: 5, 15, 30, 45 and 60 min. Aqueous extracts of the mucosae were injected into the coeliac trunk of a second series of rats while collecting pancreatic juice for amylase and trypsin activity measurements. The extracts of mucosae removed from the first series of rats 30 min after an oral glucose load and injected into the second series induced an amylase stimulation which was significantly different from that of control rats, whereas trypsin activity remained low. Conversely, extracts of mucosae removed 5 and 45 min after an oral load of lactalbumin-hydrolysate elicited a marked stimulation of trypsin, whereas amylase activity did not differ from that of control rats.

This study suggests that food promotes a rapid activation or synthesis of specific duodenal hormones which, in turn, stimulate the release of pancreatic enzymes specific for the ingested food substrates.

Key words

Intestinal Hormones - Exocrine Pancreas - Oral Glucose - Oral Protein Hydrolysate - Amylase - Trypsin - Cholecystokinin-Pancreozymin