title: The stimulatory effect of 5HT and the role of the paraventricular nucleus on PMS induced ovulation in the immature rat.
abstract: Immature rats can be induced to ovulate with pregnant mare serum (PMS) as long as they weigh over 60 g. In the rats weighing less than 60 g 5-hydroxytryptamine (5HT)-60 micrograms/rat intraventricularly or 2 micrograms/rat in the paraventricular nucleus (PVN)-stimulated ovulation. Injections into several other hypothalamic nuclei were ineffective. In rats weighing greater than 60 g, lesions of the PVN or injection of 10 micrograms/rat p-chlorophenylalanine into the PVN inhibited ovulation. The hypothalamic levels of 5HT and 5-hydroxy indole acetic acid (5HIAA) were generally lower in the afternoon and evening in the less than 60 g when compared with the greater than 60 g rats. It is possible that increased 5HT activity is required to stimulate ovulation and that its site of action is the PVN.
mesh_terms: D000818:Animals; D005260:Female; D010134:Fenclonine / Q000494:pharmacology; D006064:Gonadotropins, Equine / Q000008:administration & dosage* / Q000494:pharmacology; D006897:Hydroxyindoleacetic Acid / Q000032:analysis; D007031:Hypothalamus / Q000032:analysis / Q000502:physiology*; D007276:Injections, Intraventricular; D018377:Neurotransmitter Agents / Q000494:pharmacology; D010060:Ovulation / Q000187:drug effects*; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D012701:Serotonin / Q000008:administration & dosage* / Q000032:analysis / Q000494:pharmacology
chemical_list: D006064:Gonadotropins, Equine; D018377:Neurotransmitter Agents; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D010134:Fenclonine