Experimental gestational diabetes mellitus induces blunted vasoconstriction and functional changes in the rat aorta

Preeclampsia pravastatin early VS late treatment: Effects on oxidative stress and vascular reactivity

Early diagnosis and efficient treatment of preeclampsia remains a medical challenge and etiological factors converge in a deficient placentation that triggers oxidative stress. There is evidence that statins show antioxidant effects that can improve endothelial function without adverse perinatal effects. We aimed to compare early vs. late pravastatin treatment on the oxidative stress and cardiovascular features of an experimental model of preeclampsia. Female Wistar rats were randomly divided into preeclampsia phenotype rats (PEP) developed by sub renal aortic coarctation (SRAC) and healthy pregnant rats (C). Each group received pravastatin (5 mg/Kg) p.o. either for one week before and during the first week or during the last two weeks of gestation. Blood pressure was determined using the plethysmographic method. Phenylephrine (Phe)-induced contractility was evaluated in isolated thoracic and abdominal aortic rings with or without endothelium. Blood samples were obtained to determine anion superoxide concentration as indicator of NADPH activity. Two-way ANOVA and Bonferroni post hoc tests were used to define statistical significance. Early or late pravastatin treatment decreased hypertension of PEP animals but did not change BP of the healthy pregnant group. Thoracic and abdominal aorta from PEP rats showed increased contractility that was reverted by pravastatin early treatment in endothelium intact rings. Pravastatin did not significantly change contractility neither in the thoracic nor in the abdominal aorta segments from healthy pregnant control rats (C), and decrease anion superoxide concentration by NADPH activity. We conclude pravastatin can improve both blood pressure and endothelium-dependent Phe-induced contractility in an experimental model of preeclampsia by reducing oxidative stress.

Streptozotocin-Induced Maternal Hyperglycemia Increases the Expression of Antioxidant Enzymes and Mast Cell Number in Offspring Rat Ventral Prostate

Gestational diabetes mellitus (GDM) has increased in recent years. Although the cellular and molecular mechanisms involved in GDM-increased risk factors to offspring remained poorly understood, some studies suggested an association between an increase in oxidative stress induced by maternal hyperglycemia and complications for both mothers and newborns. Here, we investigated the impact of maternal hyperglycemia followed by maternal insulin replacement during lactation on the expression of antioxidant enzymes and mast cell number in offspring ventral prostate (VP) at puberty. Pregnant rats were divided into three groups: control (CT); streptozotocin-induced maternal hyperglycemia (MH); and MH plus maternal insulin replacement during lactation (MHI). Male offspring were euthanized at postnatal day (PND) 60 and the VP was removed and processed for histology and Western blotting analyses. Maternal hyperglycemia delayed prostate maturation, and increased mast cell number catalase (CAT), superoxide dismutase (SOD), glutatione-s-transferase (GST-pi), and cyclooxygenase-2 (Cox-2) expression in the offspring of hyperglycemic dams. Maternal insulin replacement restored VP structure, mast cell number and antioxidant protein expression, except for Cox-2, which remained higher in the MHI group. Thus, an increase in oxidative stress induced by intrauterine hyperglycemia impacts prostate development and maturation, which persists until puberty. The overall improvement of maternal metabolism after insulin administration contributes to the restoration of prostate antioxidant enzymes and secretory function. Taken together, our results highlighted that imbalanced physiological maternal-fetal interaction contributes to the impairment of reproductive performance of the offspring from diabetic mothers. Anat Rec, 300:291-299, 2017. © 2016 Wiley Periodicals, Inc.

Changes in protein and gene expression of angiotensin II receptors (AT1 and AT2) in aorta of diabetic and hypertensive rats

Diabetes and hypertension have been associated with cardiovascular diseases and stroke. Some reports have related the coexistence of hypertension and diabetes with increase in the risk of developing vascular complications. Recently some studies have shown results suggesting that in the early stages of diabetes and hypertension exist a reduced functional response to vasopressor agents like angiotensin II (Ang II), which plays an important role in blood pressure regulation mechanism through the activation of its AT1 and AT2 receptors. For that reason, the aim of this work was to study the gene and protein expression of AT1 and AT2 receptors in aorta of diabetic SHR and WKY rats. Diabetes was induced by the administration of streptozotocin (60 mg/kg i.p.). After 4 weeks of the onset of diabetes, the protein expression was obtained by western blot and the mRNA expression by RT-PCR. Our results showed that the hypertensive rats have a higher mRNA and protein expression of AT1 receptors than normotensive rats while the AT2 expression remained unchanged. On the other hand, the combination of diabetes and hypertension increased the mRNA and protein expression of AT1 and AT2 receptors significantly. In conclusion, our results suggest that diabetes with hypertension modifies the mRNA and protein expression of AT1 and AT2 receptors. However, the overexpression of AT2 could be associated with the reduction in the response to Ang II in the early stage of diabetes.