IMPAIRMENT OF TESTICULAR FUNCTION IN THE WHITE RAT CHRONICALLY EXPOSED TO A LOW AMBIENT TEMPERATURE

Abstract

The most striking observation was that long exposure to cold produced cryptorchism in normal untreated rats. Microscopically, the testes became violaceous and much atrophied, and the seminal vesicles also were atrophied; histologically, the testes showed no evidence of spermatogenesis, the seminiferous tubules were disorganized, and the germinal epithelium had disappeared; in many cases, the interstitial cells of Leydig had also disappeared. All these changes happened after 40 weeks of exposure at 2[degree]C. Twelve weeks later, that is after an exposure of 52 weeks to the same cold temperature, the testes were still in the abdominal cavity, still atrophied, and the histological picture was the same. But at the same time, surprisingly enough, the weights of the seminal vesicles of all animals, without exception, returned to normal, indicating that the endocrine function seemed to be restored to normal. The source of the androgens, in the latter case, could well have been, at least partially, outside the testes and possibly in the adrenals, where a special zone was found, between the medulla and the reticularis, in these untreated controls which had been exposed to cold for 52 weeks. It was also found that male and female sex hormones seriously impaired the survival rate of normal and castrated male rats exposed to cold for long periods.