title: Subfornical organ neurons act to enhance the activity of paraventricular vasopressin neurons in response to intravenous angiotensin II.
abstract: The effects of pretreatment of the angiotensin II (ANGII) antagonist, saralasin (Sar), in the subfornical organ (SFO) on intravenous ANGII-induced responses of the activity of phasically firing paraventricular nucleus (PVN) neurons (n = 23) antidromically identified as projecting to the posterior pituitary were examined in urethane-anesthetized rats. The activity of the majority (n = 18) of identified PVN neurons was excited by intravenously administered ANGII, whereas the remaining neurons (n = 5) were not affected. The excitatory responses (n = 13) to ANGII were prevented by pretreatment with Sar, but not by isotonic saline (n = 3), in the SFO. These results suggest that ANGII-sensitive SFO neurons may act to enhance the excitability of putative vasopressin (VP)-secreting neurons in the PVN in response to circulating ANGII.
authors: Department of Physiology, Kochi Medical School, Japan.
authors: J
authors: J
authors: Tanaka
authors: H
authors: H
authors: Saito
authors: H
authors: H
authors: Kaba
authors: K
authors: K
authors: Seto
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000804:Angiotensin II / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D007275:Injections, Intravenous; D008297:Male; D009490:Neurosecretory Systems / Q000502:physiology*; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000502:physiology*; D010904:Pituitary Gland, Posterior / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D012504:Saralasin / Q000494:pharmacology; D013356:Subfornical Organ / Q000187:drug effects / Q000502:physiology*
chemical_list: D000804:Angiotensin II; D012504:Saralasin