THE ACTIVITY OF SOME DIGESTIVE ENZYMES IN DOMESTIC RABBITS BEFORE ANDAFTER WEANING

The activity of amylase, maltase, lipase, pepsin, trypsin and chymotry psin in suckling (15 days of age) and in 1-day weaned (43 days of age) domestic rabbits was assayed and compared with older (90 and 280 days ) rabbits. It teas found that amylase was active in the pancreas at 15 days (11 580 amylase units (AU per mg protein) and increased during g rowth, reaching a maximum level (58 960 AU per mg protein) at 90 days of age. Specific activity (SA) of maltase from the small intestine muc osa varied depending on the intestinal segment and the age of the rabb its: activity in the duodenal mucosa decreased, while in the jejunal a nd ileal mucosa activity increased, during growth. Lipase SA reached a maximum level in suckling rabbits at the age of 15 days tin gastric m ucosa 242 and in pancreas 608 mequiv. liberated oleic acid per mg prot ein per h, 37 degrees C) and decreased sharply at weaning: in gastric mucosa down to 86 and in pancreas down to 89 mequiv. oleic acid per mg protein per h, 37 degrees C. SA of pepsin remained relatively constan t for all the studied categories of rabbits: 38 to 39 nmol tyrosine pe r mg protein per min, 25 degrees C. Trypsin and chymotrypsin SA reache d a peak at about weaning: 1.83 nmol benzoyl-arginyl-ethyl-ester per m g protein per min, 25 degrees C and 40.1 nmol benzoyl-phenyl-naphtyl-e ster per mg protein per min, 35.5 degrees C respectively.