Effect of gonadectomy on the follicular cell and inclusions in mitochondria of rabbit thyroid gland.

Thyroid glands of male rabbits were studied 2, 4, and 6 weeks after gonadectomy. In the gonadectomized group of animals, at the end of 2 weeks the follicular cell did not present any significant change except for the reduction of the supranuclear portion of the cell. By the end of 4 weeks there was a marked decrease in the microvilli of the apical border, dense granules, colloid droplets, ribosomes, and ergastoplasmic sacs. The lateral and basal cell margins were less convoluted. These changes reached a peak by the end of 6 weeks. The mitochondria with the inclusions also showed an apparent decrease in incidence at the end of 4 weeks and were rarely encountered by the end of 6 weeks. The thyroid gland morphologially resembled a hypothroid state, indicating that gonadectomy depresses the function and, therefore, may affect the metabolic process controlled by the gland.