Sexual Dimorphism in the Regulation of Estrogen, Progesterone, and Androgen Receptors by Sex Steroids in the Rat Airway Smooth Muscle Cells

The role of sex hormones in lung is known. The three main sex steroid receptors, estrogen, progesterone, and androgen, have not been sufficiently studied in airway smooth muscle cells (ASMC), and the sex hormone regulation on these receptors is unknown. We examined the presence and regulation of sex hormone receptors in female and male rat ASMC by Western blotting and flow cytometry. Gonadectomized rats were treated with 17β-estradiol, progesterone, 17β-estradiol + progesterone, or testosterone. ASMC were enzymatically isolated from tracheas and bronchi. The experiments were performed with double staining flow cytometry (anti-α-actin smooth muscle and antibodies to each hormone receptor). ERα, ERβ, tPR, and AR were detected in females or males. ERα was upregulated by E2 and T and downregulated by P4 in females; in males, ERα was downregulated by P4, E + P, and T. ERβ was downregulated by each treatment in females, and only by E + P and T in males. tPR was downregulated by P4, E + P, and T in females. No hormonal regulation was observed in male receptors. AR was downregulated in males treated with E + P and T. We have shown the occurrence of sex hormone receptors in ASMC and their regulation by the sex hormones in female and male rats.

Tibolone induces serotonin, estrogen, and progesterone receptor expression but not contractile response to serotonin in the rat uterus

Most studies on the effect of tibolone on the uterus have focused on the endometrium dismissing the importance of the myometrium. The aim of the present study was to investigate some estrogen-like actions of tibolone in the uterus assessed by: 1) the expression of estrogen, progesterone, and serotonin receptors, and 2) the myometrial contraction induced by serotonin. Estradiol (250 μg), progesterone (50 mg), or testosterone (25 mg) pellets were implanted to ovariectomized rats. Tibolone (0.5 mg/day) was orally administered. An implanted pellet containing vehicle or an equivalent volume of water p.o., were used as controls. Sixty days after beginning the treatments, rats were killed and uterus removed. One horn was processed to evaluate estrogen-alpha, progesterone A and B, and serotonin-2A receptors expression, and the other one was used for studying contraction to serotonin and 60 mM potassium solution. The present data showed that tibolone-induced expression of estrogen, progesterone, and serotonin receptors, but did not induce uterine contractile response to either serotonin or potassium solution. These findings suggest that, in the uterus, tibolone may exert molecular estrogenic actions such as the induction of receptor expression, but not a physiological response as the estrogen-dependent contraction to serotonin.

Hemodynamic and oxidative stress profile after exercise in type 2 diabetes

This study investigated the effect of an acute bout of exercise (>85% VO2Max) on biochemical, hemodynamic and oxidative stress variables in sedentary and physically active subjects with type 2 diabetes (T2D). Blood measurements were taken before and after a treadmill test on 12 sedentary non-diabetes subjects (ND), 12 sedentary type 2 diabetes (T2S) and 9 physically active T2D subjects (T2DA). T2DS subjects before and after the treadmill test showed a higher plasma glucose (123.2 +/- 19.0 mg/dL versus 108.9 +/- 16.8 mg/dL, p < 0.001), HbA1C (8.7 +/- 2.4% versus 7.3 +/- 1.2%, p < 0.001) and body fat% (21.3 +/- 5.7% versus 34.6 +/- 4.5%, p < 0.001) than T2DA subjects. T2DA had higher VO2Max (37.7 +/- 3.5 versus 29.5 +/- 3.2, p < 0.05), time on treadmill (22.3 +/- 2.1 min versus 16.1 +/- 2.1 min, p < 0.05), hemoglobin (17.9 +/- 0.9 g/dL, p < 0.05) and lower blood pressure levels in comparison to ND and T2DS subjects. Thiobarbituric acid substances (TBARS) in T2DS were higher than in T2DA subjects (0.27 +/- 0.1 nmol/mL versus 0.21 +/- 0.1 nmol/mL, p < 0.05). Glutathione (GSH) levels were similar among the groups. Physically active type 2 diabetes subjects had a more favorable biochemical, hemodynamic and oxidative stress profile than sedentary subjects. The coexistence of a poor cardiopulmonary performance and high oxidative stress environment can determine a profile of high risk for serious cardiovascular events in patients with diabetes.