Changes in rat pancreatic protein synthesis after a single feeding with diets containing raw or heated soybeans

Abstract

The patterns of protein synthesis following the administration of a single meal containing defatted ground soybeans (RSD) or heated defatted ground soybeans (HSD) were compared. A double label method was used so that the determination of the relative rate of synthesis of an enzyme could not be obscured by a possible alteration of the activity or quantity of the enzyme. Rats were given one meal of RSD or HSD and were subsequently killed at different times after the meal. Eight hours after the meal, the relative rate of synthesis of one of the three trypsinogens was substantially increased with RSD feeding, whereas that of the amylases and one chymotrypsinogen were somewhat lower. The synthetic rate of lipase, ribonclease, proelastase, another chymotrypsinogen and of two trypsinogens was unaffected when feeding RSD is compared to feeding HSD. The relative rate of synthesis of one of the trypsinogens was unaffected 8 hours after RSD feeding, but was increased 16 hours after RSD feeding. Actinomycin D could suppress the effects of RSD feeding on the protein synthetic rate of some, but not of all, secretory proteins.