Influences of norepinephrine, and adrenergic agonists and antagonists on gonadotropin secretion from dispersed pituitary cells of goldfish, Carassius auratus.
Static incubations of dispersed goldfish pituitary cells with 1-100 nM norepinephrine (NE) stimulated gonadotropin (GTH) release. Additions of the alpha-agonist phenylephrine, and the alpha 1-agonist 6-fluoronorepinephrine, but not the alpha 2-agonist clonidine, nor the beta-agonist isoproterenol, also enhanced GTH secretion. The GTH responses to 1 nM NE was significantly inhibited by coincubations with 1 microM of the alpha-antagonist phentolamine, the alpha 1-antagonists prazosine and benoxathian, but not the alpha 2-antagonist yohimbine nor the beta-antagonist propranolol. The GTH responses to NE and phenylephrine were also additive to salmon GTH-releasing hormone (sGnRH)-induced GTH release. These results suggests that NE directly stimulates GTH secretion independent of sGnRH receptors via alpha 1-like adrenergic receptors.
Department of Zoology, University of Alberta, Edmonton, Canada.
J P
JP
Chang
F
F
Van Goor
S
S
Acharya
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D004347:Drug Interactions; D006054:Goldfish / Q000502:physiology*; D006062:Gonadotropins / Q000378:metabolism*; D009638:Norepinephrine / Q000031:analogs & derivatives / Q000494:pharmacology*; D010075:Oxathiins / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism*; D011224:Prazosin / Q000494:pharmacology
D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D006062:Gonadotropins; D010075:Oxathiins; D010656:Phenylephrine; C024884:6-fluoronorepinephrine; C050877:benoxathian; D009638:Norepinephrine; D011224:Prazosin; D010646:Phentolamine