Enhanced acetylcholine induced relaxation in small mesenteric arteries from pregnant rats: an important role for endothelium‐derived hyperpolarizing factor (EDHF)

Abstract

1 Small mesenteric arteries from pregnant rats demonstrated greater sensitivity (pEC₅₀ : PPPω‐nitro L‐arginine methyl ester (L‐NAME, 100 μM), indomethacin (INDO, 10 μM) and oxadiazole quinoxalin (ODQ, 1 μM), suggesting pregnancy associated enhancement of dilator prostanoid and/or nitric oxide (NO) synthesis. 3 ACh induced relaxation in 5 mM KCl was only partially inhibited by a combination of N^ω‐nitro L‐arginine methyl ester (L‐NAME, 100 μM), indomethacin (INDO, 10 μM) and oxadiazole quinoxalin (ODQ, 1 μM). The residual relaxation, which was greater in arteries from pregnant rats (maximum relaxation: PPBritish Journal of Pharmacology (1998) 125, 455–460; doi:10.1038/sj.bjp.0702099