Prochymosin and pepsinogen potential activity and electrophoretic study of proteolytic fractions in the gastric and duodenal mucosal extracts from the first four day old lambs.

Potential proteolytic activity of prochymosin (PCh) and pepsinogen (PG) as well as relative activity of the proteolytic fractions in the mucosal extracts of the whole stomach, pyloric region of the stomach and duodenum were investigated. The main activity in the lambs stomach after birth demonstrated PCh however a small amount of PGA activity was also present. The highest activity of PCh from the whole stomach was observed in day 2 and 3, PG activity from the whole and pyloric region of the stomach increased in the first day of life and later was not significant by changed. Mucosal extracts of the whole stomach contained 3 to 4 of pepsinogen fractions of the fast migration (Pg1, Pg2, Pg3 and Pg4) in which Pg3 was of the highest activity in the majority of lambs. Pyloric region revealed 3 fractions: Pg2, of a small and Pg3 and Pg4 of high and equal activity. In duodenum Pg3 and Pg4 were of equal activity. The beginning of Pg2, Pg3 and Pg4 relative activity changes were observed in lambs stomach in respect to increase of Pg2 and decrease of Pg3 activity. The group of 3-4 fractions of slow electrophoretic migration contained probably progastricsin of small--and prochymosin of the highest activity within this group and a small non-pepsinogen fraction.