Alterations in vasomotor systems and mechanics of resistance-sized mesenteric arteries from SHR and WKY male rats following in vivo testosterone manipulation

Table 2 Effective concentration needed to constrict to 50% of total diameter with phenylephrine in SHR and WKY treatment groups^a

Treatment	Strain	CONT	CAST	CAST + T
EC₅₀	SHR	830 ± 36 nM (n = 10)	827 ± 60 nM (n = 6)	1,570 ± 433 nM (n = 6)**
	WKY	844 ± 45 nM (n = 10)	734 ± 66 nM (n = 6)*	740 ± 41 nM (n = 6)*

^aCAST, castrate; CAST + T, castrate plus testosterone; CONT, control; EC₅₀, effective concentration needed to constrict to 50% of total diameter; SHR, spontaneously hypertensive rat; WKY: Wistar Kyoto. Data are means ± SEM. SHR CAST + T was significantly higher than SHR CONT (**P < 0.01). WKY CONT was significantly higher than CAST (*P < 0.05).