Central choline reverses hypotension caused by α-adrenoceptor or ganglion blockade in rats: the role of vasopressin

• Published in: European journal of pharmacology 1996-09, Vol.311 (2), p.153-161
• Main Authors: Savci, Vahide, Ulus, Ismail H.
• Format: Article
• Language: English
• Subjects: Acetylcholine; Adrenergic alpha-Antagonists - pharmacology; Adrenergic beta-Antagonists - pharmacology; Analysis of Variance; Animals; Biological and medical sciences; Blood pressure; Blood Pressure - drug effects; Choline; Choline - antagonists & inhibitors; Choline - pharmacology; Dose-Response Relationship, Drug; Fundamental and applied biological sciences. Psychology; Ganglionic Blockers - pharmacology; Heart Rate - drug effects; Hemodynamics. Rheology; Hexamethonium - pharmacology; Hypotension; Hypotension - chemically induced; Hypotension - drug therapy; Male; Mecamylamine - pharmacology; Nicotinic Antagonists - pharmacology; Nicotinic receptor; Nootropic Agents - antagonists & inhibitors; Nootropic Agents - pharmacology; Phentolamine - pharmacology; Propranolol - pharmacology; Rats; Vasoconstrictor Agents - blood; Vasoconstrictor Agents - pharmacology; Vasopressin; Vasopressins - blood; Vasopressins - pharmacology; Vertebrates: cardiovascular system
• ISSN: 0014-2999; 1879-0712
• DOI: 10.1016/0014-2999(96)00424-4

The effect of intracerebrovenricularly (i.c.v.) injected choline on blood pressure was investigated in rats made hypotensive by blocking peripheral α-adrenoceptors or autonomic ganglionic transmission. Choline (50–150 μg; i.c.v.) increased blood pressure in a dose-dependent manner and 150 μg of choline restored blood pressure to the resting level. The pressor response to choline was associated with an increase in plasma vasopressin levels. Pretreatment with mecamylamine (50 μg; i.c.v.), but not atropine (10 μg; i.c.v.), blocked both the pressor and vasopressin responses to i.c.v. choline. The vasopressin receptor antagonist, [β-mercapto-β,β-cyclopenta-methylene-propionyl 1,O-Me-Try 2,Arg 8]vasopressin (10 μg/kg; i.v.), given 5 min after i.c.v. choline (150 μg), abolished the pressor effect of choline and blood pressure returned to the pre-choline levels. It is concluded that the precursor of acetylcholine, choline, can increase blood pressure and reverse hypotension in α-adrenoceptor or ganglionic transmission blocked rats, by increasing plasma vasopressin.