Fig. 6

17β-estradiol after cardiac arrest and cardiopulmonary resuscitation (CA/CPR) ameliorates renal injury in old mice of both sexes. Blood and tissue samples were collected 24 h after CA/CPR in aged (78–87 weeks) male or female mice intravenously injected with 10 μg of 17β-estradiol or vehicle 15 min after return of spontaneous circulation. Unlike in young mice, in this group of mice at advanced age, there was no significant effect of sex on renal injury. Estradiol treatment significantly reduced serum creatinine (b) and tubular cell death (c) in aged males (triangle) and tubular cell death (c) in aged females (circle). Serum urea nitrogen was not affected by estrogen treatment in either aged males or aged females (a). Data are presented as mean ± standard deviation, n = 8–10 per group, *P < 0.05 by two-way analysis of variance with post hoc Sidak’s test. EST 17β-estradiol-treated mice, VEH vehicle-treated mice