TY - JOUR
T1 - Differential effects of bromocriptine treatment on LH release and copulatory behavior in hyperprolactinemic male rats
AU - Doherty, P. C.
AU - Bartke, A.
AU - Smith, M. S.
N1 - Funding Information:
We wish to thank Drs. D. M. Quadagno, J. Herbert, and D. Bailey for communicating their unpublished results to us. The surgical assistance of Arturo Moreno is also gratefully acknowledged. Bromocriptine was the gift of Dr. Richard Elton of Sandoz Pharmaceuticals, East Hanover, New Jersey; and material for radioimmunoassay of rat prolactin, LH, and FSH was generously supplied by the hormone distribution program of NIAMDD, and Dr. A. F. Parlow. We also wish to thank Ms. Lynn Rudloff and Ms. Gretta Small for their help in preparing this manuscript. This work was supported by NICHHD through Grant HD12671 and the Bioassay Core of Grant P30-HD10202.
PY - 1981/12
Y1 - 1981/12
N2 - Hyperprolactinemia (hyperPRL) induced by grafting four pituitary glands under the kidney capsule suppresses copulatory behavior in male rats and sexually naive male mice. In mice sexual experience attenuates the suppressive effects of hyperPRL on mating behavior, thus a comparison of the behavioral consequences of inducing hyperPRL in sexually naive and experienced male rats was undertaken. Hyperprolactinemia had a significant suppressive effect on mating behavior in both groups of animals. Experienced animals showed deficits in all parameters studied except mount frequency and postejaculatory interval, while naive animals differed from respective controls only in mount latency, intromission latency, and intromission frequency. To determine if the inhibition of chronically elevated prolactin (PRL) levels would reverse the suppression of gonadotropin secretion and copulatory behavior in hyperprolactinemic animals, the effects of bromocriptine (CB-154) administration on plasma hormone levels and mating behavior were examined in pituitary-grafted and control rats. Bromocriptine treatment (1 mg/day for 14 days) led to increases in sexual activity in both the sham-operated and grafted animals. In the grafted animals, plasma PRL was reduced and plasma LH significantly increased in the CB-154-treated animals when compared to oil-treated controls. In sham-operated animals, CB-154 produced no significant changes in plasma LH or FSH despite the suppressed PRL levels. These results indicate that (1) hyperPRL induced by pituitary grafts can cause deficits in mating behavior in male rats despite previous sexual experience, and (2) while CB-154 may be acting through other mechanisms to stimulate copulatory behavior, the reduction of chronically elevated PRL levels due to CB-154 treatment is responsible for reversal of the suppressive effects of hyperPRL on LH secretion.
AB - Hyperprolactinemia (hyperPRL) induced by grafting four pituitary glands under the kidney capsule suppresses copulatory behavior in male rats and sexually naive male mice. In mice sexual experience attenuates the suppressive effects of hyperPRL on mating behavior, thus a comparison of the behavioral consequences of inducing hyperPRL in sexually naive and experienced male rats was undertaken. Hyperprolactinemia had a significant suppressive effect on mating behavior in both groups of animals. Experienced animals showed deficits in all parameters studied except mount frequency and postejaculatory interval, while naive animals differed from respective controls only in mount latency, intromission latency, and intromission frequency. To determine if the inhibition of chronically elevated prolactin (PRL) levels would reverse the suppression of gonadotropin secretion and copulatory behavior in hyperprolactinemic animals, the effects of bromocriptine (CB-154) administration on plasma hormone levels and mating behavior were examined in pituitary-grafted and control rats. Bromocriptine treatment (1 mg/day for 14 days) led to increases in sexual activity in both the sham-operated and grafted animals. In the grafted animals, plasma PRL was reduced and plasma LH significantly increased in the CB-154-treated animals when compared to oil-treated controls. In sham-operated animals, CB-154 produced no significant changes in plasma LH or FSH despite the suppressed PRL levels. These results indicate that (1) hyperPRL induced by pituitary grafts can cause deficits in mating behavior in male rats despite previous sexual experience, and (2) while CB-154 may be acting through other mechanisms to stimulate copulatory behavior, the reduction of chronically elevated PRL levels due to CB-154 treatment is responsible for reversal of the suppressive effects of hyperPRL on LH secretion.
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U2 - 10.1016/0018-506X(81)90008-8
DO - 10.1016/0018-506X(81)90008-8
M3 - Article
C2 - 6799382
AN - SCOPUS:0019857545
SN - 0018-506X
VL - 15
SP - 436
EP - 450
JO - Hormones and Behavior
JF - Hormones and Behavior
IS - 4
ER -