Effects of microelectrophoretically applied acetylcholine- and angiotensin-antagonists on the paraventricular neurosecretory cells excited by osmotic stimuli.
Extracellular action potentials were recorded from neurons identified antidromically as neurosecretory cells in the paraventricular nucleus of urethane-anesthetized rats. An intracarotid injection of 0.6 M NaCl increased the firing rate of 26 out of the 33 neurosecretory cells tested. The excitation induced by hypertonic NaCl was blocked by hexamethonium in 6 of 10 neurosecretory cells with nicotinic-cholinergic receptors, by atropine in 4 of 5 cells with muscarinic-cholinergic receptors and by [Sar1, Ala8]-angiotensin II in 5 of 12 cells with angiotensin II receptors. These results suggest that nicotinic- or muscarinic-cholinergic receptors and/or angiotensin II receptors appear to be involved in the final transmission of osmotic stimuli in the paraventricular neurosecretory cells.
D000109:Acetylcholine / Q000037:antagonists & inhibitors*; D000804:Angiotensin II / Q000037:antagonists & inhibitors*; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D005260:Female; D018738:Hexamethonium; D006584:Hexamethonium Compounds / Q000494:pharmacology; D009489:Neurosecretion / Q000187:drug effects*; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D011945:Receptors, Angiotensin / Q000187:drug effects; D011950:Receptors, Cholinergic / Q000187:drug effects; D012504:Saralasin / Q000494:pharmacology; D013495:Supraoptic Nucleus / Q000187:drug effects; D009435:Synaptic Transmission / Q000187:drug effects; D014882:Water-Electrolyte Balance / Q000187:drug effects*
D057911:Angiotensin Receptor Antagonists; D006584:Hexamethonium Compounds; D011945:Receptors, Angiotensin; D011950:Receptors, Cholinergic; D000804:Angiotensin II; D018738:Hexamethonium; D001285:Atropine; D012504:Saralasin; D000109:Acetylcholine