Sexually dimorphic distribution of sst2A somatostatin receptors on growth hormone-releasing hormone neurons in mice.
The pulsatile pattern of GH secretion exhibits sexual dimorphism that is likely to depend on somatostatin (SRIH) effects on somatoliberin (GHRH) neurons in the hypothalamus. Using transgenic GHRH-enhanced green fluorescent protein (eGFP) mice, no difference in the total number of GHRH-eGFP neurons or change in somatostatin receptor sst2 and SRIH mRNA levels in ventromedial hypothalamic nucleus-arcuate nucleus and periventricular nucleus regions and GHRH mRNA levels in the ventromedial hypothalamic-arcuate region were observed between male and female mice. However, the percentage of GHRH-eGFP neurons bearing sst2A receptors reached 78% in female vs. 26% in male GHRH-eGFP mice (P < 0.02). This sex difference in sst2A distribution on GHRH neurons may play an important role in the sexually differentiated pattern of GH secretion.
Unité Mixte de Recherche 549, Institut National de la Santé et de la Recherche Médicale, Faculté de Médecine, Université Paris René Descartes, Institut Fédératif de Recherche Broca Sainte Anne, 75014 Paris, France.
Karine
K
Bouyer
Catherine
C
Loudes
Iain C A F
IC
Robinson
Jacques
J
Epelbaum
Annie
A
Faivre-Bauman
D000818:Animals; D005260:Female; D013006:Growth Hormone / Q000378:metabolism; D013007:Growth Hormone-Releasing Hormone / Q000032:analysis* / Q000235:genetics; D007031:Hypothalamus / Q000737:chemistry*; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000032:analysis; D017481:Receptors, Somatostatin / Q000032:analysis*; D012727:Sex Characteristics; D013004:Somatostatin / Q000235:genetics
D012333:RNA, Messenger; D017481:Receptors, Somatostatin; C106140:somatostatin receptor sst2A; D013004:Somatostatin; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone