Modulation of prolactin luteinizing hormone and follicle stimulating hormone secretion by luteinizing hormone releasing hormone and bromocriptine cb 154 in the hypophysectomized pituitary grafted male rat and its effect on testicular luteinizing hormone receptors and testosterone output
Sharpe R.M.
Biology of Reproduction 21(1): 141-148
1979
ISSN/ISBN: 0006-3363 Document Number: 434461
Hypophysectomized adult male rats with a pituitary transplant under the kidney capsule were used to study the effects of chronic treatment with LHRH without increasing testis weight. Administration of LHRH was associated with an increase in testis weight and with the capacity of the whole testis to bind hCG. Administration of CB154 to rats having transplants and receiving 5 .mu.g LHRH reduced testicular binding of hCG without affecting testis weight. Basal testicular T secretion in vitro was increased in all groups receiving pituitary transplants. hCG-stimulated T secretion in vitro was increased significantly over hypophysectomized controls only when gonadotropin secretion was maintained by LHRH treatment with or without CB154. Small amounts of LHRH stimulated a greater and more prolonged increase in the levels of FSH than of LH; something from the pituitary transplant, presumably PRL, induces or maintains LH receptors in the testis without affecting testis weight or hCG-stimulated T secretion in vitro; LHRH treatment and the increased gonadotropin secretion caused by it, increase testis weight with an associated increase in LH binding and ability to secrete T after hCG stimulation in vitro.