title: The nitric oxide pathway participates in estrous behavior induced by progesterone and some of its ring A-reduced metabolites.
abstract: Intracerebral and intravenous administration of progesterone (P) and its ring A-reduced metabolites induces intense sexual behavior (lordosis and proceptivity) in estrogen-primed rats. The present study tested the hypothesis that the nitric oxide-cGMP-protein kinase G pathway is involved in the facilitation of sexual behavior induced by the intracerebroventricular (i.c.v.) administration of P (130 ng) and its ring A-reduced metabolites 5alpha-dihydroprogesterone (5alpha-DHP; 13 ng) and 5alpha,3alpha-pregnanolone (5alpha,3alpha-Pgl; 13 ng). In Experiment 1, we tested the relevance of the nitric oxide/cGMP pathway by infusing a nitric oxide synthase inhibitor or a nitric oxide-dependent, soluble guanylyl cyclase inhibitor icv before progestin administration. The lordosis induced by P, 5alpha-DHP and 5alpha,3alpha-Pgl was significantly reduced at 2 h after progestin infusion by the previous injection of either a nitric oxide synthase inhibitor or by a soluble guanylyl cyclase inhibitor. Lordosis behavior returned to control values by 4 h. In Experiment 2, i.c.v. infusion of the protein kinase G inhibitor KT5823 significantly inhibited the lordosis behavior induced by all three progestins at 2 h. These data support the hypothesis that the nitric oxide/cGMP/protein kinase G pathway is involved in the lordosis induced by P and some of its ring A-reduced metabolites.
authors.affiliation: Department of Neuroscience F113, Albert Einstein College of Medicine (AECOM), Bronx, NY 10461, USA.
authors.forename: Oscar
authors.initials: O
authors.lastname: González-Flores
authors.forename: Anne M
authors.initials: AM
authors.lastname: Etgen
mesh_terms: D043582:5-alpha-Dihydroprogesterone / Q000008:administration & dosage / Q000502:physiology; D000818:Animals; D006152:Cyclic GMP / Q000378:metabolism*; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004971:Estrus / Q000502:physiology; D005260:Female; D007276:Injections, Intraventricular; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D011187:Posture; D011280:Pregnanolone / Q000008:administration & dosage / Q000502:physiology; D011374:Progesterone / Q000008:administration & dosage / Q000502:physiology; D045167:Progesterone Congeners / Q000008:administration & dosage / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D004791:Enzyme Inhibitors; D045167:Progesterone Congeners; D009569:Nitric Oxide; D011374:Progesterone; D043582:5-alpha-Dihydroprogesterone; D011280:Pregnanolone; D017869:Cyclic GMP-Dependent Protein Kinases; D006152:Cyclic GMP; D019331:NG-Nitroarginine Methyl Ester