Figure 8.

Effect of apamin and charybdotoxin on CPA-induced increase in NO on the rat superior mesenteric artery. Original recordings of two different vascular segments showing increase in NO concentration, measured with the same microsensor, to CPA (a) in the presence and the absence of extracellular calcium, and (b) in the absence and the presence of apamin (500 nM) and charybdotoxin (100 nM). The ACh was added at the height of the CPA-induced increase in NO concentration. (c) Average of increases in NO concentration to CPA in the absence and the presence of extracellular calcium, and apamin plus charybdotoxin. The experiments were performed in the presence of 3 μM indomethacin. The points are means±s.e.m. of arteries from four to six animals. ^*P<0.05 versus control, Student's t-test.