title: Neurons in the hypothalamic paraventricular nucleus mediate the serotonergic stimulation of renin secretion.
abstract: The aim of the present study was to resolve which hypothalamic nucleus is necessary for the serotonergic control of renin secretion. RU 24969 is considered a serotonin (5-HT1A/5-HT1B) agonist, while p-chloroamphetamine is a 5-HT releaser. Both drugs reliably elevate plasma levels of renin when injected peripherally. Previous studies suggest that serotonergic neurons, projecting to the hypothalamus, mediate the effect of p-chloroamphetamine on renin secretion. Discrete cell-selective lesions were made with ibotenic acid in three hypothalamic sites: the paraventricular, the dorsomedial or the ventromedial nuclei. Two weeks after surgery rats were injected with RU 24969 (5 mg/kg, i.p.) or p-chloroamphetamine (8 mg/kg, i.p.). The renin response to both RU 24969 and p-chloroamphetamine was significantly reduced in rats with histologically verified paraventricular lesions compared to vehicle treated controls. In contrast, the renin response to p-chloroamphetamine remained unchanged in rats with either dorsomedial or ventromedial hypothalamic lesions. Thus, these results are consistent with the hypothesis that 5-HT receptors located on cell bodies in the paraventricular nucleus mediate the renin response to a serotonin agonist and releaser. Furthermore, they confirm previous studies that suggest that 5-HT neurons regulate renin secretion through central receptors.
authors.affiliation: Department of Pharmacology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153.
authors.forename: P A
authors.initials: PA
authors.lastname: Rittenhouse
authors.forename: Q
authors.initials: Q
authors.lastname: Li
authors.forename: A D
authors.initials: AD
authors.lastname: Levy
authors.forename: L D
authors.initials: LD
authors.lastname: Van de Kar
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D007051:Ibotenic Acid; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012083:Renin / Q000378:metabolism*; D012701:Serotonin / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D010133:p-Chloroamphetamine / Q000494:pharmacology*
chemical_list: D007211:Indoles; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D007051:Ibotenic Acid; C025145:5-methoxy 3-(1,2,3,6-tetrahydro-4-pyridinyl)1H indole; D012701:Serotonin; D010133:p-Chloroamphetamine; D012083:Renin