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Neuroendocrinology

Influences of norepinephrine, and adrenergic agonists and antagonists on gonadotropin secretion from dispersed pituitary cells of goldfish, Carassius auratus.


PMID 1682833

Abstract

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.