Efeito associativo da dexametasona e melatonina exógenas sobre ratas prenhes

Abstract

Dexamethasone is widely used in processes anti-inflammatory, immunosuppressive and in cases of pregnancy with risk of prematurity. Supraphysiological doses of dexamethasone can provide complications and affect embryogenesis. Melatonin, produced by the pineal gland, has been shown to prevent the deleterious effects of glucocorticoids. We evaluated the influence of melatonin on systemic effects of dexamethasone to pregnant rats through the following parameters: 1. Hematocrit and glucose profile, 2. Levels of progesterone and 3. Histomorphometry and histochemistry of organs. We used 20 rats divided into two groups: I - pregnant rats untreated (control), II - pregnant rats treated with dexamethasone (0.8mg/kg) lll - pregnant rats treated with melatonin (0.5 mg / kg) IV: pregnant rats treated with dexamethasone and melatonin. All treatments were initiated 10 days after confirmation of mating until the end of pregnancy. Blood was collected in the 7th, 14th and 21st days. Determination of carbohydrate was accomplished by anthrone method for reading plate. Progesterone was measured by ELISA. The liver, kidneys and adrenals were examined histochemically and morphometrically. The results showed a protection of melatonin to blood parameters (hematocrit, total RBC, total and differential leukocyte count), biochemical and hormonal. Treatment with dexamethasone caused a gradual reduction in the total number of red blood cells and anisocytosis, neutrophilia, lymphopenia and eosinopenia, and reduced plasma levels of carbohydrates on day 21 and progesterone at 14 and 21 days of gestation. No evidence of morphological and histochemical changes in the organs. Dexamethasone at a dosage of 0.8 mg / kg applied from the middle third of pregnancy produces hematological, biochemical and hormonal in rats, however, does not affect the liver, kidneys and adrenals, as to histochemical and morphometric parameters. These effects were prevented by melatonin.