Open AccessMicroinjection of resveratrol into rostral ventrolateral medulla decreases sympathetic vasomotor tone through nitric oxide and intracellular Ca 2+ in anesthetized male rats 1
Author(s) -
MA Huijuan,
CAO Yakun,
LIU Yixian,
WANG Ru,
WU Yuming
Publication year - 2008
Publication title -
acta pharmacologica sinica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.514
H-Index - 90
eISSN - 1745-7254
pISSN - 1671-4083
DOI - 10.1111/j.1745-7254.2008.00827.x
Subject(s) - microinjection , rostral ventrolateral medulla , endocrinology , medicine , nitric oxide , chemistry , sodium orthovanadate , angiotensin ii , nitric oxide synthase , heart rate , protein tyrosine phosphatase , blood pressure , receptor
Aim: To define the effect of resveratrol (RES) on the central regulation of blood pressure (BP), heart rate (HR), and renal sympathetic nerve activity (RSNA). Methods: RES was microinjected into the rostral ventrolateral medulla (RVLM), and BP, HR, and RSNA were recorded simultaneously in anesthetized rats. Results: A microinjection of RES (20, 40, and 80 μmol/L, 0.2 μL) into the RVLM dose dependently decreased BP, HR and RSNA. Pretreatment with an anti‐estrogen tamoxifen (100 μmol/L, 0.2 μL) did not affect the effects of RES. Pretreatment with N G ‐nitro‐ L ‐arginine methyl ester (100 μmol/L, 0.2 μL), an inhibitor of nitric oxide (NO) synthase, could completely abolish the effect of RES. A prior microinjection of Bay K8644 (500 nmol/L, 0.2 μL), an agonist of calcium channels, could also abrogate the effect of RES. Prior administration of a potent inhibitor of tyrosine phosphatase, sodium orthovanadate (1 mmol/L, 0.2 μL), could partially attenuate the inhibitory effect of RES. Conclusion: The results suggest that a microinjection of RES into the RVLM inhibits BP, HR, and RSNA. The effects may be mediated by NO synthesis and a decrease in Ca 2+ influx, in which protein tyrosine kinase is involved.