[Studies on the physical dependence liability of analgesics. 5th report: Electron microscopic studies on the ultrastructural transformation of mitochondria in the cells of zona fasciculata of the adrenal cortex in morphine pellet implanted mice (author's transl)].

Influence of morphine on the fine structure of mitochondria in the cells of zona fasciculata of the adrenal cortex in mice in which a morphine pellet was subcutaneously implanted was studied using electron microscope. (1) Transformation of the mitochondrial structure, i.e. swelling, formation of lamellar or concentric circular cristae and decrease of electron density of the mitochondrial matrix, was observed 12 hr after implantation, and changes reached a maximum state at 48 hr. These transformations, however, disappeared wihtin 4 days. (2) On the 4th day after implantation, removal the pellet again produced transformation of the mitochondria with withdrawal symptoms, and a normal state was reverted to 72 hr later. Levallorphan challenge produced similar changes. (3) Injection of morphine into mice after removal of the pellet prevented the appearance of mitochondrial transformation. From the results obtained it may be concluded that there are correlations between the transformation of the mitochondria and physical dependence on morphine in mice.