How does apelin affect LH levels? An investigation at the level of GnRH and KNDy neurons. (1st November 2022)

• Record Type: Journal Article
• Authors: Abot, Anne; Robert, Vincent; Fleurot, Renaud; Dardente, Hugues; Hellier, Vincent; Froment, Pascal; Duittoz, Anne; Knauf, Claude; Dufourny, Laurence
• Is Part Of: Molecular and cellular endocrinology. Volume 557(2022)
• Publication Date: 2022-11-01
• Subjects: Adipokines -- Kisspeptin -- Dynorphin -- Neurokinin B -- Hypothalamus -- Reproduction -- Rodents; KP kisspeptin -- ARC arcuate nucleus -- GPCR G-Protein Coupled Receptor -- AVPV antero ventral periventricular area -- Dyn dynorphin -- NKB neurokinin B -- POMC proopiomelanocortin -- OVLT organum vasculosum of the lamina -- i.c.v. intracerebroventricular -- FSK forskolin -- NOS nitric oxide synthase -- APs action potentials -- PKA protein kinase A; Endocrinology -- Periodicals; Molecular biology -- Periodicals; Cytology -- Periodicals; Endocrinology -- Periodicals; Hormones -- Periodicals; Endocrinologie -- Périodiques; Cytology; Endocrinology; Molecular biology; Periodicals; 573.4
• DOI: 10.1016/j.mce.2022.111752
• Languages: English
• ISSNs: 0303-7207

Abstract

Abstract: Hypothalamic control of reproduction relies on GnRH and kisspeptin (KP) secretions. KP neurons are sensitive to sex steroids and metabolic status and their distribution overlaps with neurons producing apelin, a metabolic hormone known to decrease LH secretion in rats. Here, we observed neuroanatomical contacts between apelin fibers and both KP and GnRH neurons in the hypothalamus of male rodents. Intracerebroventricular apelin infusion for 2 weeks in male mice did not decrease LH levels nor did it affect gene expression for KP, neurokinin B and dynorphin. Finally, increasing apelin concentrations did not modulate Ca 2+ levels of cultured GnRH neurons, while 10 μM apelin infusion on forskolin pretreated GnRH neurons revoked a rhythmic activity in 18% of GnRH neurons. These results suggest that acute apelin effect on LH secretion does not involve modulation of gene expression in KP neurons but may affect the secretory activity of GnRH neurons. Highlights: Apelin terminals are present both on KNDy and GnRH neurons in male rats and mice. Apelin chronic infusion does not decrease LH blood levels in male mice. Apelin chronic infusion does not affect gene expression in KNDy neurons. Apelin acute treatment modifies electrical activity in 18% of GnRH neurons.