Histological changes in the testis of the domestic fowl after partial adenohypophysectomy.
The effects of partial adenohypophysectomy on comb size, testicular weight, and histology 20 or 30 days after the operation are described and discussed in relating these observed changes with the volume of remaining adenohypophyseal tissue. From the present observation, it is concluded that 1) the response of the domestic fowl to partial deficiency of adenohypophyseal tissue may be more sensitive than that of some mammals, 2) the decrease in testicular weight and tubular diameter precedes the histological change in testis and comb regression, and 3) to maintain fully active testicular function, more than 75% of the adenohypophysis is needed. About 40% of the adenohypophyseal tissue including a remnant of cephalic lobe can stimulate spermatogenesis, but the spermatozoa produced were partially abnormal. The critical amount of adenohypophyseal tissue for normal spermiogenesis may exist between 55 and 75%. All histological change is initially observed in the center of testis and then extended toward the periphery. It is suggested that the cephalic lobe contains at least a trace of ICSH in addition to FSH.
D000818:Animals; D002645:Chickens / Q000601:surgery; D007016:Hypophysectomy / Q000662:veterinary*; D008297:Male; D010903:Pituitary Gland, Anterior / Q000601:surgery*; D013091:Spermatogenesis; D013737:Testis / Q000473:pathology*