Secretoneurin stimulates goldfish pituitary luteinizing hormone production.
Secretoneurin (SN), a 33-34 amino acid neuropeptide is derived from endoproteolysis of secretogranin II (SgII), a member protein of the chromogranin family. SN is widely distributed in various tissues of vertebrates especially in pituitary and hypothalamus, and is a potential new hormone. In vivo, i.p. injection of SN increased luteinizing hormone (LH) release in goldfish pretreated with the dopamine antagonist domperidone. In 6-h static incubation of goldfish pituitary fragments, 10 and 100 nM but not 1 nM concentrations of goldfish SN had a direct stimulatory effect to increase LH release by 2.3- and 1.5-fold (p<0.05), respectively. In addition, 500 nM SN induced a 2.6-fold increase in LHbeta subunit messenger RNA (mRNA) levels in pituitary fragments, regardless of whether LHbeta mRNA levels were expressed relative to 18S ribosomal RNA or beta-actin mRNA. We suggest that the stimulatory actions of SN on LH release may be a part of a paracrine or autocrine feedback loop in the pituitary.
Zhao
E
E
Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa, Ont., Canada K1N 6N5.
Basak
Ajoy
A
Trudeau
Vance L
VL
D000818:Animals; D004294:Domperidone / Q000378:metabolism / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000378:metabolism / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006054:Goldfish / Q000033:anatomy & histology / Q000378:metabolism; D007986:Luteinizing Hormone / Q000235:genetics / Q000378:metabolism*; D037101:Luteinizing Hormone, beta Subunit / Q000235:genetics / Q000378:metabolism; D008297:Male; D009479:Neuropeptides / Q000494:pharmacology*; D010902:Pituitary Gland / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D053381:Secretogranin II / Q000494:pharmacology*; D046509:Tissue Culture Techniques
D018492:Dopamine Antagonists; D037101:Luteinizing Hormone, beta Subunit; D009479:Neuropeptides; D021122:Protein Subunits; D012333:RNA, Messenger; D053381:Secretogranin II; C081159:secretoneurin; D004294:Domperidone; D007986:Luteinizing Hormone