1. Microinjection of resveratrol into rostral ventrolateral medulla decreases sympathetic vasomotor tone through nitric oxide and intracellular Ca2+ in anesthetized male rats.
- Author
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Ma HJ, Cao YK, Liu YX, Wang R, and Wu YM
- Subjects
- Anesthesia, Animals, Blood Pressure drug effects, Drug Interactions, Heart Rate drug effects, Male, Microinjections, Muscle, Smooth, Vascular innervation, Nitric Oxide Synthase Type III antagonists & inhibitors, Rats, Rats, Sprague-Dawley, Renal Circulation drug effects, Resveratrol, Stilbenes administration & dosage, Calcium Signaling drug effects, Enzyme Inhibitors pharmacology, Medulla Oblongata physiology, Muscle Tonus drug effects, Muscle, Smooth, Vascular drug effects, Nitric Oxide physiology, Stilbenes pharmacology, Sympathetic Nervous System drug effects
- Abstract
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 micromol/L, 0.2 microL) into the RVLM dose dependently decreased BP, HR, and RSNA. Pretreatment with an anti-estrogen tamoxifen (100 micromol/L, 0.2 microL) did not affect the effects of RES. Pretreatment with NG-nitro- L-arginine methyl ester (100 micromol/L, 0.2 microL), 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 microL), 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 microL), 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 Ca2+ influx, in which protein tyrosine kinase is involved.
- Published
- 2008
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