Nalbuphine-induced submicroscopic changes in the components of the thymus vascular bed

Abstract

Notwithstanding the widespread use of opioid analgesics in medical practice and the increased incidence of drug addiction, especially among teenagers, the issue of the influence of opioids on the immune organs remains relevant. 52 white male rats of reproductive age with an initial body weight of 140–150 g were involved into study. Nalbuphine was administered intramuscularly once daily at 10:00 –11:00 hours during 42 days, increasing the dose every 7 days. The material was collected in accordance with conventional technique. After one week of the introduction of Nalbuphine a moderate thickening of the basal membrane and enlargement of the lumen of blood capillaries was observed. Within the two weeks the lumen of arteries, arterioles and venules was slightly dilated, the nuclei of the endotheliocytes were slightly enlarged, occupying a significant portion of the cytoplasm; invaginations were formed by the karyolemma. After three to four weeks the veins and venules were dilated, plethoric, interendothelial bonds in the vascular wall were enlarged, the basal membrane was damaged, deformed red blood cells were found in the lumen of the hemocapillaries, arranged in the ―coin column‖, often attached to the luminal surface of the endotheliocytes. The wall of arteries and arterioles were thickened due to the edema of endotheliocytes and initial signs of sclerosis. After five to six weeks the perivascular edemas and hemorrhages into the parenchyma thymus was detected. The vast majority of vessels vere ―empty‖. One week after the drug was discontinued, no irreversible changes were found.