Response of isolated renal arterioles to XXXX , @entity935 , and @entity1812 .

@entity935 @entity95 @entity1617 @entity1769 @entity3897 @entity1812 @entity1063 @entity934
The effect of @entity934 ( @entity1617 ), @entity935 (DA), and @entity1812 (BK) on vascular tone was examined in interlobular arteries and superficial afferent and efferent arterioles isolated from @entity95 kidney. A single microvessel was dissected and cannulated, and lumen diameter was measured at a fixed intraluminal pressure. @entity1617 caused a dose-dependent relaxation of @entity1063 -induced tone in all three vessel types. Significant relaxation (10-20%) was observed with 10(-8) M @entity1617 and higher concentrations caused complete relaxation. In afferent and efferent arterioles DA caused a dose-dependent relaxation that was indistinguishable from the one caused by @entity1617 . However, DA was much less effective on interlobular arteries. Significant relaxation was not observed until 10(-5) M DA, and 10(-4) M caused only a 30-40% relaxation. In afferent arterioles @entity3897 blocked the effect of @entity1617 , and @entity1769 selectively inhibited DA-induced relaxation. BK (10(-9) to 10(-5) M) caused a dose-dependent relaxation of @entity1063 -induced tone only in efferent arterioles. BK, either in the bath or lumen, had no effect on the preglomerular microvessels. @entity1617 and DA also caused relaxation of afferent arterioles with spontaneous tone while all three vasodilators relaxed efferent arterioles with spontaneous tone. The results demonstrate segmental heterogeneity for these vasodilators in the @entity95 renal microvasculature, with @entity1617 causing relaxation in all three vessel types, DA acting primarily on the glomerular arterioles, and BK affecting only the efferent arteriole.
