Localization of tritiated prostaglandin E₁ in rat adrenal cortices: Autoradiographic and biochemical studies

To determine whether or not prostaglandins enter adrenocortical parenchymal cells,³H-PGE₁ was injected intravenously into rats. In histological preparations, grains denoting activity were noted in intracellular lipid droplets and nuclei and in sinusoids. At the fine structural level, activity was observed in lipid droplets, mitochondria, the agranular endoplasmic reticulum, nuclei and the plasma membrane. Biochemical lipid analyses of the adrenals revealed activity in the cholesterol and cholesterol ester fractions. Large amounts of unaltered³H-PGE₁ and its degradation products were also present. Compared to the liver, the adrenal was more effective in degrading prostaglandin, when expressed on a weight basis. The possible roles of the organelles in PGE₁ degradation and in prostaglandin-related hormone synthesis are discussed.