Effects of cigarette smoke exposure on the utlrastructure of the golden hamster parathyroid gland

Summary. Cigarette smoking has been identified as one of the risk factors to induce osteoporosis. Howe ver, we find no study on the morphology of the parathy r o i d gland under smoking exposure. We studied the ultrastructure of the parathyroid gland, lung and femur of the golden hamster exposed to cigarette smoke. Four week-old male hamsters were housed in a plastic case (48x31x30 cm) and were exposed to cigarette smoke for 12 weeks, 5 minutes exposure, 4 times a day, 4 days a week. There were no differences in serum calcium level and the whole bone mineral density between the control and the smoke-exposed groups. In the parathyroid gland of the smoke - exposed animals, the Golgi complexe s associated with many prosecretory granules were well d eveloped and many secretory granules were located near the plasma membrane. Large lipid-like inclusion bodies were observed in the alveolar macrophages of the smoke-exposed animals. The femur morphology showed a wider area of resorbing surface in the smoke-exposed group than in the control group. From these findings, it is conceivable that the secretory activity of the p a r a t hyroid gland was stimulated with cigarette smoke exposure.