Parallel secretion of digestive enzymes by the in vitro rabbit pancreas.

Nonparallel discharge of digestive enzymes by the in vitro rabbit pancreas has been previously reported and this observation has been used to challenge the mass transport theory of enzyme synthesis and secretion by the exocrine pancreas. The current investigation reexamines the pattern of enzyme secretion from the in vitro rabbit pancreas. Secretion of alpha-amylase, trypsinogen, and chymotrypsinogen was studied from the unstimulated gland and from glands stimulated with either methacholine, cholecystokinin-pancreozymin, or the active octapeptide of cholecystokinin-pancreozymin. In all cases, only parallel discharge of alpha-amlyse, trypsinogen, and chymotrypsinogen was noted. These observations are consistent with the mass-transport theory.