[Effects of angiotensin II, atrial natriuretic peptide and arginine vasopressin on activity of subfornical organ neurons in rat brain slices].
The effects of angiotensin II (AG II), atrial natriuretic peptide (ANP) and arginine vasopressin (AVP) on 87 subfornical organ (SFO) neurons from 31 brain slices of rats were observed. After perfusing the brain slices with AG II (10(-7) mol/L, 3 min), spontaneous discharge rate of 40/55 (72.73%) neurons was significantly increased, while that of 3/55 (5.45%) was decreased and 12/55 (21.82%) neurons were non-responsive. The excitatory effects of AG II on neurons in SFO were completely blocked by AG II receptor blocker saralasin (10(-6) mol/L). As the brain slices were perfused with atrial peptide III (AP III) (10(-7) mol/L, 3 min), the firing rate of 7/17 (41.18%) neurons was significantly decreased, while that of 2/17 (11.76%) neurons was increased and 8/17 (47.06%) neurons were non-responsive. By perfusing brain slices with AVP (10(-7) mol/L, 3 min), the firing rate of 8/15 (53.33%) neurons was significantly increased, while that of 3/15 (20.00%) neurons was decreased and 4/15 (26.67%) neurons were non-responsive. Twelve SFO neurons were successively perfused with three peptides. Among them, one was excited by both AG II and AVP, 3 were excited by AG II and inhibited by AP III, and the other one was excited by AVP and inhibited by AP III. The results suggest that the discharge rate of SFO neurons is affected by AG II, ANP and AVP. SFO may be one of the central regions in regulation of water balance and blood pressure.
Yang
L M
LM
Department of Physiology, Hebei Medical College, Shijiazhuang.
Wang
Z A
ZA
Ho
S Y
SY
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D004594:Electrophysiology; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009474:Neurons / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012504:Saralasin / Q000494:pharmacology
D000804:Angiotensin II; D001127:Arginine Vasopressin; D009320:Atrial Natriuretic Factor; D012504:Saralasin