Ropivacaine-Induced Contraction Is Attenuated by Both Endothelial Nitric Oxide and Voltage-Dependent Potassium Channels in Isolated Rat Aortae

Figure 5

Cumulative concentration-response curves induced by 4-aminopyridine (4-AP) and tetraethylammonium (TEA) in endothelium-denuded aortae precontracted with 1×10⁻⁴ M ropivacaine. Data are shown as the mean ± SD and expressed as a percentage of the maximal contraction induced by ropivacaine (1×10⁻⁴ M) (100% = 0.94±0.28 g (𝑛=10) and 100% = 0.97±0.25 g (𝑛=10) for endothelium-denuded aortae with 4-AP and TEA, resp.). N indicates the number of descending thoracic aortic rings. ^∗𝑃<0.001 versus ropivacaine (1×10⁻⁴ M).