[Mechanism of folliculogenesis in the rat thyroid in long-term hypercalcemia].

Two types of folliculogenesis specific for the peripheral and central zones of the rat thyroid gland under prolonged hypercalcemia are described. The folliculogenesis is realized via fragmentation of a large follicle into several small ones penetrated with cords of the connective tissue. The new follicles are formed with various intensity. When the folliculogenesis is intensive, a distinctly seen desquamation of the follicular epithelium is observed. Thyrocalcitonin secreted by C-cells is probably the initiative factor of the folliculogenesis. A suggestion is made on a leading role of C-cells in pathogenesis of the goiter.