[Effect of vitamin A on the testes].

Experiments were made on adult male mice with experimental unilateral cryptorchism. The animals were divided into three groups. The first group served as control, the second group of animals received mater-soluble retinoic acid in the total dose 0.1 ml (1% solution), and the third group in the total dose 0.3 ml (1% solution). Eight days after operation the tests were taken for histological and morphometry examination. In the course of experiments, spermatogenic processes in the tests had stopped because of degeneration of differential and mature sexual cells. Meanwhile spermatogonia and sustenocytes of the seminiferous tubules and glandulocytes of the tests had been preserved. Administration of the acid in a dose of 0.1 ml did not increase the resistance of the spermatogenic epithelium to the unfavourable conditions, but maintained its capacity for regeneration. After administration of the acid in a dose of 0.3 ml the animals manifested the signs of hypervitaminosis, the resistance of the spermatogenic epithelium to the action of unfavourable factors decreased and the regenerative capacity was inhibited.