Failure of neuropeptide Y to modulate the release of LH and prolactin by cultured bovine pituitary cells.
Possible direct effects of neuropeptide Y (NPY) on dispersed and cultured cells of the anterior lobe (AL) of the bovine pituitary were investigated. AL tissue from steers was enzymatically dissociated into individual cells, preincubated for 18 hr and then incubated in suspension cultures for 2 hr or 24 hr with either NPY, gonadotropin-releasing hormone (GnRH) or both. Release of luteinizing hormone (LH) and prolactin (PRL) into medium was quantified by radioimmunoassay and expressed as hormone released per 100,000 cells. Basal release of LH averaged 38 and 86 ng for 2 hr and 24 hr respectively while that of PRL averaged 118 and 438 ng for the same incubation periods. Addition of NPY did not alter (P greater than .05) basal release of LH or PRL for either duration of incubation. Also, NPY did not affect (P less than .05) release of of LH in response to GnRH. In summary, this study indicated that NPY, at in vitro dosages of .01 to 100 nM, does not modulate the release of LH or PRL at the pituitary level in castrate cattle.
D000818:Animals; D002417:Cattle / Q000502:physiology*; D002478:Cells, Cultured; D007986:Luteinizing Hormone / Q000378:metabolism*; D008297:Male; D009478:Neuropeptide Y / Q000494:pharmacology*; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011388:Prolactin / Q000378:metabolism*
D009478:Neuropeptide Y; D011388:Prolactin; D007986:Luteinizing Hormone