Medroxyprogesterone induced changes in rat liver. A light and electron microscopic study

Abstract

Medroxyprogesterone acetate (MPA) induced morphological alterations in the normal female rat liver and after carbon tetrachloride exposure were assessed by light and electron microscopy and morphometry. Administration of MPA increased the smooth endoplasmic reticulum (SER) in normal rat. Carbon tetrachloride, injected intraperitoneally for four weeks, caused fatty accumulation, enlargement of the cell nucleus and decrease of the rough endoplasmic reticulum (RER) and increase of the SER. After one week of recovery, without treatment, the fatty infiltration and the SER membranes decreased and the RER increased. MPA, following injury, induced a decrease in the fatty accumulation and mitochondrial volume density and the hepatocyte nuclear and cytoplasm size normalized. The SER membrane volume density increased and the surface density decreased, the RER membrane volume density increased while the surface density did not alter significantly. The volume densities of the mitochondria and the peroxisomes decreased in the MPA treated CCl4 exposed groups. The results demonstrate that MPA induces a proliferation of the SER in normal rat liver and after hepatic injury the compound has a beneficial effect on the regeneration.