Effects of hemin on cGMP levels in the aortas from SHRs and WKYs.

(A) Changes in cGMP contents in 20- and 8-week-old SHRs and WKYs. (B) Changes in cGMP contents in 4-week-old SHRs and WKYs. The administration of hemin significantly enhanced the cGMP level in aortas from 4- and 8-week-old SHRs and the respective age-matched WKYs, but not 20-week-old SHRs or WKYs. *P < .05 versus all other groups. †P < .05 versus age-matched and hemin-treated WKYs. ††P < .05 versus any other groups without hemin treatment. ΔP < .05 versus age-matched animals of the same species but without hemin treatment. The ages of the animals in weeks were indicated as “20” and “8” in (A). n = 4 for each group. Error bars indicate means ± SEM.