Research Article

Effects of ABCB1 3435C>T genotype on serum levels of cortisol and aldosterone in women with normal menstrual cycles

Abstract

ABCB1, also known as MDR1/P-glycoprotein, can transport cortisol and aldosterone. We examined the effects of ABCB1 polymorphisms on serum levels of cortisol and aldosterone among different phases of the normal menstrual cycle in 51 non-pregnant healthy Japanese female volunteers (22 ± 1 years old). The menstrual cycle was divided into three phases: premenstrual phase (14 days preceding the onset of menstruation, N = 22; menstrual phase, N = 11, and postmenstrual phase, N = 18). ABCB1 -129T>C, 1236C>T, 2677G>A/T, and 3435C>T genotypes were determined. Serum levels of cortisol, aldosterone, estradiol, progesterone, and testosterone were measured. The serum levels of estradiol in the pre- and post-menstrual phases and of progesterone in the premenstrual phase were significantly increased when compared to their serum levels in the menstrual phase (P 0.005). In the postmenstrual phase, the mean serum cortisol level in subjects with the 3435CT and 3435TT genotype was 7.6 ± 3.4 μg/dL (mean ± SD, N = 7), which was significantly lower than in women with the 3435CC genotype (9.9 ± 1.8 μg/dL, N = 11) (P = 0.037). The opposite effect was observed in the serum aldosterone level during the postmenstrual phase (97.2 ± 23.4 and 141.2 ± 48.5 pg/mL for 3435CC and 3435CT + 3435TT, respectively; P = 0.041). These findings suggest that ABCB1 3435C>T genotype can influence serum levels of cortisol and aldosterone during the postmenstrual phase of the normal menstrual cycle.

ABCB1, also known as MDR1/P-glycoprotein, can transport cortisol and aldosterone. We examined the effects of ABCB1 polymorphisms on serum levels of cortisol and aldosterone among different phases of the normal menstrual cycle in 51 non-pregnant healthy Japanese female volunteers (22 ± 1 years old). The menstrual cycle was divided into three phases: premenstrual phase (14 days preceding the onset of menstruation, N = 22; menstrual phase, N = 11, and postmenstrual phase, N = 18). ABCB1 -129T>C, 1236C>T, 2677G>A/T, and 3435C>T genotypes were determined. Serum levels of cortisol, aldosterone, estradiol, progesterone, and testosterone were measured. The serum levels of estradiol in the pre- and post-menstrual phases and of progesterone in the premenstrual phase were significantly increased when compared to their serum levels in the menstrual phase (P 0.005). In the postmenstrual phase, the mean serum cortisol level in subjects with the 3435CT and 3435TT genotype was 7.6 ± 3.4 μg/dL (mean ± SD, N = 7), which was significantly lower than in women with the 3435CC genotype (9.9 ± 1.8 μg/dL, N = 11) (P = 0.037). The opposite effect was observed in the serum aldosterone level during the postmenstrual phase (97.2 ± 23.4 and 141.2 ± 48.5 pg/mL for 3435CC and 3435CT + 3435TT, respectively; P = 0.041). These findings suggest that ABCB1 3435C>T genotype can influence serum levels of cortisol and aldosterone during the postmenstrual phase of the normal menstrual cycle.