ABSTRACT
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.
Subject(s)
Estrogen Receptor alpha/genetics , Gene Expression/drug effects , Norpregnenes/pharmacology , Receptors, Progesterone/genetics , Receptors, Serotonin/genetics , Uterine Contraction/drug effects , Uterus/drug effects , Animals , Estrogen Receptor alpha/metabolism , Estrogens/pharmacology , Female , Rats , Rats, Sprague-Dawley , Receptors, Progesterone/metabolism , Receptors, Serotonin/metabolism , Uterus/physiologyABSTRACT
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.
