Evidence that nitric oxide is involved in the regulation of growth hormone secretion in goldfish.
Whether nitric oxide (NO) plays a role in regulation of growth hormone (GH) secretion from somatotropes in the pituitary of the goldfish Carassius auratus was investigated. Immunocytochemistry with two antibodies against mammalian NO synthase (NOS) revealed the presence of a NOS-like enzyme in primary cultures of dispersed goldfish pituitary cells, including morphologically identified somatotropes. NO donors S-nitroso-N-acetylpenicillamine and sodium nitroprusside (SNP), as well as a cyclic guanosine monophosphate analogue (dibutyryl guanosine 3':5'-cyclic monophosphate), all significantly increased GH secretion from dispersed goldfish pituitary cells in static culture. Somatostatin abolished the response to SNP, and NOS inhibitors aminoguanadine hemisulfate (AGH) and N-(3-aminomethyl)benzylacetamidine, dihydrochloride (1400W) decreased the GH release response to known neuroendocrine factors stimulatory to GH release (gonadotropin-releasing hormone and a dopamine D1 agonist). AGH and 1400W did not alter basal GH secretion. These data suggest that NO plays a role in mediating the GH response to endogenous neuroendocrine factors in goldfish.
Uretsky
A D
AD
Department of Biological Sciences, University of Alberta, Edmonton, Canada.
Chang
J P
JP
D000818:Animals; D002478:Cells, Cultured; D003995:Dibutyryl Cyclic GMP / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006054:Goldfish / Q000502:physiology*; D013006:Growth Hormone / Q000378:metabolism*; D006146:Guanidines / Q000494:pharmacology; D006706:Homeostasis; D007150:Immunohistochemistry; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000037:antagonists & inhibitors; D052247:Nitric Oxide Synthase Type II; D010902:Pituitary Gland / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D013004:Somatostatin / Q000494:pharmacology
D004791:Enzyme Inhibitors; D006146:Guanidines; D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D003995:Dibutyryl Cyclic GMP; D013004:Somatostatin; D013006:Growth Hormone; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C004479:pimagedine