Dose-dependent effect of Reserpine on the Ultrastructure of the Myocardial Cells

Abstract

Reserpine was administered to guinea-pigs subcutaneously using the following regimes: 10 mg/kg/day for 14 days; 50 mg/kg/day for 14 days; 200 mg/kg/day for 7 days and 2 mg/kg/day for 3 days and 7 days. The results showed that the extent of structural alteration was dependent on the dose and duration of treatment. At low dose, the main structural change was an increase ir. glycogen granules. As the dose was increased, there was also an increase in lipid droplets. However, if the dose of reserpine given exceeded 2 mg/kg/day for 3 days, the increase in glycogen granules observed earlier with lower doses was no longer apparent but the increase in lipid droplets remained. At low doses, only a few myocardial cells showed structural alteration in mitochondria, swollen tubular systems and presence of autophagic vacaoles but at high doses, these changes were more frequently observed in many of the myocardial cells. The basement membrane and sarcolemma of the myocardial cells were not structurally altered.