Nitric oxide : biology and chemistry
-
Angiotensin-(1-7) is a bioactive component of the renin-angiotensin system that is formed endogenously and induces nitric oxide release in several tissues. The L-arginine/NO/cyclic GMP pathway and ATP-sensitive K+ channels have been proposed as the mechanism of action for the peripheral antinociception of several groups of drug and endogenous substances, including opioids, non-steroidal analgesics, acetylcholine and others. The aim of the present study was to investigate the involvement of the L-arginine/NO/cGMP and KATP+ pathway on antinociception induced by angiotensin-(1-7). ⋯ In addition, the level of nitrite in the homogenized paw tissue, as determined by a colorimetric assay, indicated that exogenous Ang-(1-7) is able to induce NO release. The soluble guanylyl cyclase inhibitor ODQ and the specific blocker of ATP-sensitive K+ channels glibenclamide (40, 80 and 160 μg/paw) antagonized the Ang-(1-7) response. The results provide evidence that Ang-(1-7) most likely induces peripheral antinociceptive effects via the L-arginine/NO/cGMP pathway and KATP+ pathway activation.