Kisspeptin pathways are involved in E2B- and P-induced lordosis in E2B-primed females.

MCH pathways are involved in E2B- and P-induced lordosis in E2B-primed females.

Hypothalamic peptides involved in energy balance modulate ovulation and sexual behavior.

Intracerebroventricular (ICV) administration of estradiol benzoate (E2B) and progesterone (P) induces intense lordosis behavior in ovariectomized rats primed peripherally with E2B. The present study tested the hypothesis that the Kisspeptin (Kiss) and melanin-concentrating hormone (MCH) pathways regulate female sexual behavior induced by these steroid hormones. In Experiment 1, we tested the relevance of the Kiss pathway by ICV infusion of its inhibitor, kiss-234, before administration of E2B or P in estrogen-primed rats. Lordosis induced by E2B alone or with the addition of P was reduced significantly at 30, 120, and 240 min. In Experiment 2, ICV infusion of MCH 30 min before E2B or P significantly reduced lordosis in rats primed with E2B alone. These data support the hypothesis that the Kiss and MCH pathways, which can release or modulate gonadotropin-releasing hormone (GnRH), are involved in E2B- and P-induced lordosis.

Lordosis

Kisspeptin

Melanin-concentrating hormone

Estradiol

Progesterone

© 2022 Elsevier Inc. All rights reserved.