Effect of different potassium channel blockers on kaempferol-induced relaxation in the isolated coronary artery of goat

Abstract

Current study was designed to investigate the effect of different potassium channel blockers on the kaempferol-induced relaxation in the isolated coronary artery of goat. Experiments were performed in the organ bath system by mounting the isolated coronary artery of the goat heart. Small rings of the coronary artery were made and mounted in the tissue bath with the help of stainless steel hooks and tension was recorded using the power lab system. Relaxation response to kaempferol was elicited in the absence and presence of the various potassium channels blockers such as TEA (BKCa channel blocker), glibenclamide (KATP channel blocker), 4-aminopyridine (KV channel blocker) and BaCl2 (KIR channel blocker). Maximal relaxation induced by kaempferol in KCl precontracted coronary artery was 116.88±10.15%, n=6 in control. However, TEA (1 mM) did not influence the relaxation (113.18±11.55%, n=6) response of kaempferol in the coronary arterial rings of the goat. Further, glibenclamide and BaCl2 were not able to reduce the relaxation response induced by the kaempferol in this vessel. Nevertheless, 4-aminopyridine (KV channel blocker) significantly (p<0.001) decreased the relaxation response in the goat isolated coronary arterial rings in comparison with control. In conclusion, present investigation suggests that relaxation-induced by the kaempferol in goat coronary artery had shown involvement of Kv channels.