Ovulation delay induced by blockade of the cholinergic system on dioestrus-1, is related to changes in dopaminergic activity of the preoptic anterior-hypothalamic area of the rat

• Published in: Brain research bulletin Vol. 54; no. 4; pp. 339 - 344
• Main Authors: Cruz, Marı́a Esther, Villegas, Gerardo, Domı́nguez-González, Alejandro, Chavira, Roberto, Domı́nguez, Roberto
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.03.2001; Elsevier Science
• Subjects: 17β-Oestradiol; 3,4-Dihydroxyphenylacetic Acid - metabolism; Animals; Atropine - pharmacology; Atropine-sulphate; Biological and medical sciences; Diestrus - drug effects; Diestrus - metabolism; Dopamine - metabolism; Estradiol - blood; Female; Fundamental and applied biological sciences. Psychology; Gonadotropin-Releasing Hormone - drug effects; Gonadotropin-Releasing Hormone - metabolism; Hormone metabolism and regulation; Luteinizing hormone; Luteinizing Hormone - blood; Luteinizing Hormone - drug effects; Mammalian female genital system; Muscarinic Antagonists - pharmacology; Oestrous cycle; Ovulation - drug effects; Ovulation - metabolism; Preoptic Area - drug effects; Preoptic Area - metabolism; Rats; Receptors, Muscarinic - drug effects; Receptors, Muscarinic - metabolism; Vertebrates: reproduction; Atropine-sulphate; Luteinizing hormone; 17β-Oestradiol; Oestrous cycle; Dopamine; Rat; Rodentia; Central nervous system; Gonadotropin; Hypothalamus; Catecholamine; Diestrus; Estradiol; Ovulation; Vertebrata; Mammalia; Adenohypophyseal hormone; Preoptic nucleus; Neurotransmitter; Estrous cycle; Brain (vertebrata); Cholinergic transmission
• ISSN: 0361-9230; 1873-2747
• DOI: 10.1016/S0361-9230(00)00378-6

One hour after the injection of 100 mg/kg of atropine-sulphate at 1300 h of dioestrus-1, there was an abrupt increase of 17β-oestradiol plasma level and a significant increase in dopaminergic neural activity in preoptic anterior-hypothalamic area, without changes in luteinizing hormone serum level, in comparison with the saline injected group. Animals injected with atropine-sulphate showed a second increase in dopaminergic neural activity in the preoptic anterior-hypothalamic at 1100 of dioestrus-2 (atropine-sulphate 0.471 ± 0.7 vs. saline 0.241 ± 0.03, p < 0.01). In this group of animals, the preovulatory surges of 17β-oestradiol and luteinizing hormone occurred simultaneously at 1700 h of the expected day of oestrus; spontaneous ovulation was delayed until the expected day of dioestrus-1. Present results suggest that during dioestrus-1 there is a functional relationship between the cholinergic and dopaminergic systems in preoptic anterior-hypothalamic area, regulating the release of luteinizing hormone resulting in ovulation.