Cholinergic involvement in osmotic control of vasopressin release by the organ-cultured rat hypothalamo-neurohypophyseal system.
A nicotinic-cholinergic receptor appears to mediate osmotic stimulation of vasopressin (VP) release by the hypothalamo-neurohypophyseal explant. Nicotinic blocking agents, hexamethonium, tetraethylammonium chloride, and trimethaphan, blocked VP release in response to the addition of sufficient NaCl to yield a 10 mosm/kg H2O increase in culture medium osmolality. Atropine at a similar molar concentration was ineffective in blocking VP release in response to the same osmotic stimulus. Tetraethylammonium chloride and trimethaphan also blocked acetylcholine-stimulated VP release. These findings support the hypothesis that the osmoreceptive element responsible for controlling VP release resides in a separate cell and communicates with the VP cell by way of a nicotiniccholinergic receptor.
D000818:Animals; D006584:Hexamethonium Compounds / Q000494:pharmacology; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009924:Organ Culture Techniques; D009994:Osmolar Concentration; D010904:Pituitary Gland, Posterior / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011950:Receptors, Cholinergic / Q000378:metabolism*; D011978:Receptors, Nicotinic / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology; D013757:Tetraethylammonium Compounds / Q000494:pharmacology; D014294:Trimethaphan / Q000494:pharmacology; D014667:Vasopressins / Q000378:metabolism*
D006584:Hexamethonium Compounds; D011950:Receptors, Cholinergic; D011978:Receptors, Nicotinic; D013757:Tetraethylammonium Compounds; D014667:Vasopressins; D012965:Sodium Chloride; D014294:Trimethaphan