[Changes in the ultrastructure of the hypothalamus during chronic morphine poisoning].

Using electron microscopy the author studied the changes in the ultrastructure of the ventromedial hypothalamic nucleus in Wistar rats with chronic morphine intoxication (induced by unchanged or build-up doses) and upon discontinuation of morphine. Chronic morphine intoxication exerted an adverse effect on the cellular protein synthesis as well as on vesicular, granular and membranous components of cells. A correlation was detected between the pathomorphological alterations and the morphine dose. The study revealed a high sensitivity to morphine of neurons, large dendrites and interneuronal links in the period of dependence formation and the greatest vulnerability of cells and their processes during abstinence, particularly under conditions of a sharp discontinuation of morphine build-up dosage. Destructive processes observed in the experiment were also attended by manifestations of the compensatory, reparative and restorative processes detected on the 7th day after morphine discontinuation.