Interactions between @entity251 , @entity53 , and inhibin in the control of gonadotrophin secretion in males are poorly understood. Castrated rams were treated with @entity134 -free @entity291 follicular fluid (bFF), @entity251 , or @entity53 and for 7 d (2 x 2 x 2 factorial design). Given independently, none of the exogenous hormones affected follicle-stimulating hormone (FSH) concentrations, but the combination of one or both @entity230 with bFF reduced FSH secretion. @entity251 and @entity53 reduced luteinizing hormone (LH) pulse frequency (there was no synergism), and bFF had no effect. Plasma @entity31008 concentrations were not affected by any treatment. To locate the central sites of @entity134 action, castrated rams were bilaterally implanted in the preoptic area (POA), ventromedial nucleus (VMH), or arcuate nucleus (ARC). These implants did not affect FSH or @entity31008 concentrations, or LH pulse amplitude. The frequency of the LH pulses was not affected by @entity251 in any site. @entity53 located in the ARC, but not the POA or VMH, decreased LH pulse frequency. In summary, FSH secretion is controlled by synergistic interactions between inhibin and @entity53 or @entity251 , whereas @entity1176 /LH pulse frequency is controlled by testicular @entity230 . @entity53 acts partly, at least, in the ARC, but the central site of action, @entity251 remains unknown.

Gonadotrophin and XXXX secretion in castrated male sheep following subcutaneous or intracranial treatment with testicular hormones.

@entity251 :: ('MESH:D013739', 'Chemical') :: ['testosterone', 'Testosterone'] @entity53 :: ('MESH:D004958', 'Chemical') :: ['Estradiol', 'estradiol'] @entity134 :: ('CHEBI:35341', 'Chemical') :: ['steroid'] @entity31008 :: ('443317(Tax:9940)', 'Gene') :: ['prolactin'] @entity1176 :: ('MESH:D007987', 'Chemical') :: ['GnRH'] @entity230 :: ('MESH:D013256', 'Chemical') :: ['steroids'] @entity291 :: ('9913', 'Species') :: ['bovine']
@entity31008 :: (443317(Tax:9940),Gene) :: ['prolactin']
