NG-nitro-L-arginine.pdf

523Acta Physiologica Sinica, August 25, 2005, 57 (4): 523-528 Research Paper Received 2004-12-10 Accepted 2005-04-20 *Corresponding author. Tel: +86-311-6265829; E-mail: wqs413926@163.com Resveratrol inhibits the electrical activity of subfornical organ neurons in rat LI Ming1, WANG Qing-Shan1,*, CHEN Yi2, WANG Ze-Min1, LIU Zheng1, GUO Shu-Mei1 1Department of Physiology, Institute of Basic Medicine; 2Department of Pathology, Hebei Medical University, Shijiazhuang 050017, China Abstract: The effects of resveratrol on the discharges of neurons in rat subfornical organ (SFO) slices were examined by using extracellular recording technique. The results are as follows: (1) In response to the application of resveratrol (1, 5, 10 μmol/L, n=65) into the superfusate for 2 min, the spontaneous discharge rate of 60/65 (92.3%) neurons was significantly decreased in a dose- dependent manner; (2) Application of L-glutamate (0.3 mmol/L) into the superfusate led to a marked increase in discharge rate of all 12 (100%) neurons in an epileptiform pattern. The increased discharges of 10/12 (83.3%) neurons were suppressed by application of resveratrol (5 μmol/L); (3) In 8 neurons, the selective L-type calcium channel agonist, Bay K8644 (0.1 μmol/L), induced a significant increase in discharge rate of all 8 (100%) neurons. The increased discharges of all 8 (100%) neurons were suppressed by resveratrol (5 μmol/L); (4) In 14 neurons, nitric oxide synthase (NOS) inhibitor NG-nitro-L-arginine methyl ester (L-NAME) 50 μmol/L significantly increased the discharge rate of 11/14 (78.6%) neurons. Resveratrol (5 μmol/L) applied into the superfusate reduced the increased discharges of 9/11 (81.8%) neurons; (5) In 12 neurons, the large-conductance Ca2+-activated K+ channel blocker tetraethylammonium chloride (TEA) 1 mmol/L significantly increased the discharge rate of 10/12 (83.3%) neurons. Resveratrol (5 μmol/L) inhibited the increased discharges of 9/10 (90%) neurons. These results