Studies on the effect of reserpine on the peroxidase activity of submaxillary gland

In an earlier report we have described how the administration of reserpine (0.5 mg/kg) stimulates the peroxidase activity of rat and mouse submaxillary gland [R. Chakraborty, B. Mukherjee and R. N. Hati, Life Sci. 35, 1913 (1984)]. Further studies have been carried out in this area. This stimulation of the enzyme activity started from 0.02 mg reserpine/kg body wt. The effect of reserpine was found in all subcellular fractions of submaxillary gland. Iodinating activity of the enzyme preparation was also increased by reserpine treatment. Kinetic studies indicate that reserpine increased the Vmax of the enzyme without altering Km. Protein synthesis inhibitors inhibited the increase of the enzyme activity by reserpine. Dibutyryl c-AMP, theophylline or both drugs together did not alter the peroxidase activity. The effect of reserpine was also found in experiments using slices and single cell preparations of submaxillary gland, suggesting that the drug is probably acting directly on the acinar cells.