Abstract
Investigations in the field of testicular physiology have borne out that the germinative and the endocrine systems are highly independent of each other, despite the obvious parallelism in their embryonic development. Cryptorchidism and X-ray sterilization result in many cases in complete degeneration of the germ cells, without affecting, however, the endocrine system, as evidenced by the normal development and persistence of the secondary sex characters (seminal vesicle and prostate tests). On the other hand, Moore and Samuels 1 recently have shown that vitamin B deficiency inhibits selectively the endocrine system so that the male rats assume the castrate type while spermatogenesis proceeds normally.
The close time correlation in endocrine and spermatogenetic development is simply due to the fact that both are under the control of the hypophysis. The hypophysis stimulates the testicular development and answers with an increased hormone production if the testes are ablated. This reaction is most strikingly demonstrated in parabiosis experiments. Hill 2 has shown that the normalcy of the oestrus cycles of a rat female is undisturbed by a male parabiont. After castration of the male, however, the female falls into anoestrus for a period and then goes into permanent oestrus. These reactions are apparently due to the influx of excessive amounts of hypophysis hormone from the castrate, which initially cause lutein-ization of the ripe follicles and later the formation of cystic follicles.
One has generally been inclined to assume that the hyperactivity of the hypophysis is an answer to the deficiency or the complete absence of the endocrine component of the testis. It appeared of interest, therefore, to determine weather the hypophysis responds also to the absence of the germinal component only.
A series of 9 rat males, 2 months old, were sterilized, by the administration of 2400 r units of X-rays in 3 treatments.
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