Serum isoamylase activities during infusions of glucose and amino acids

This investigation was undertaken to examine the influence of intravenously administered glucose and amino acids on serum isoamylase activities. Significantly decreased serum pancreatic isoamylase was observed during administration of 20% glucose and 8% amino acid solutions intravenously for 2 h as compared with physiological saline solution (P less than 0.005). A significant negative correlation was found between mean values of pancreatic isoamylase (P-isoamylase) in serum and glucose in plasma (r = 0.91, P less than 0.01). We propose that glucose may block the flux of pancreatic amylase across the basolateral membrane of the acinar cell into the blood stream. The mechanisms by which amino acids may decrease P-isoamylase activity in serum are not quite clear. Amino acid stimulated release of pancreatic glucagon which has an inhibitory effect on amylase secretion is highly probable.