Time Course of Active Amylase Accumulation by Rat Submaxillary Gland During Continuous Pilocarpine Stimulation

Abstract

Administration of pilocarpine for varying periods results in a continuous orderly increase in the amylase levels of rat submaxillary glands without prior depletion or accompanying appreciable changes in gland wet weights. This amylase increase with time appears to occur in two phases: the first phase is characterized by a possible brief initial lag followed by a period of logarithmic increase leading to a plateau within 90 minutes. A second phase of rapid rise occurs within 3 hours. The S-shaped curve of the first phase suggests the time course of an autocatalytic process and may indicate (a) synthesis, or (b) activation of a precursor or bound enzyme form. Sodium oleate, urea, trypsin, n-butanol, heat and pH activate precursors of other enzymes but neither activated nor significantly inhibited amylase of gland homogenates. Atropine in vivo effected complete inhibition of the pilocarpine-induced amylase accumulation. Amylase accumulation under these conditions suggests enzyme synthesis.