[Effect of microinjection of atrial natriuretic peptide into the paraventricular nucleus on baroreflex sensitivity in conscious rats].
The role of atrial natriuretic peptide (ANP) in the central regulation of the circulation is known to be a neurotransmitter or a neuromodulator, but its actions on baroreceptor reflex function are not fully resolved. The present study examined the role of ANP (6, 60 ng/0.2 microl) by direct microinjection into the hypothalamic paraventricular nucleus (PVN) in conscious rats. OPC-21268 (0.45 microg/3 microl), an antagonist of the V(1) receptor, was microinjected into the lateral ventricle to examine whether the effect of ANP on baroreflex sensitivity is mediated by vasopressin (VP). ANP significantly increased the baroreflex sensitivity, and OPC-21268 attenuated the increase of baroreflex sensitivity induced by ANP. Intravenous injections of ANP (60 ng/0.04 ml) did not affect baroreflex sensitivity. These results suggest that ANP in the PVN may produce a facilitative effect on baroreflex, and the effect may be via, at least in part, the central vasopressin.
Jiang
Hai-Ying
HY
Department of Physiology, Yanbian University Medical School, Yanji 133000, China.
Jin
Qing-Hua
QH
Li
Ying-Jun
YJ
Xu
Dong-Yuan
DY
Jin
Yuan-Zhe
YZ
Jin
Xiu-Ji
XJ
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology / Q000502:physiology*; D017704:Baroreflex / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008845:Microinjections; D010286:Paraventricular Hypothalamic Nucleus / Q000502:physiology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
D009320:Atrial Natriuretic Factor