Effects of sleep restriction during pregnancy on lipids and glucose homeostasis of female offspring submitted to ovariectomy.

Sleep shortening during pregnancy may alter the mother's environment, affecting the offspring. Thus, the present study evaluated the metabolic profile of female offspring from sleep-restricted rats during the last week of pregnancy. Pregnant Wistar rats were distributed into two groups: control (C) and sleep restriction (SR). The SR was performed 20 h/day, from 14th to 20th day of pregnancy. At 2 months, half of the offspring were subjected to ovariectomy (OVX); the others, to sham surgery. Studied groups were Csham, Covx, SRsham and SRovx. Cholesterol (HDL, LDL and C-total), triglycerides (TG) and glucose and insulin tolerance tests (GTT-ITT) were evaluated at 8 months. RSsham presented higher values of TG, while SRovx presented higher TG, LDL and C-total. Basal glucose concentration was increased in SRsham and SRovx. These data suggest that SR during pregnancy may be a risk factor for the development of diseases in adult female offspring.

Treatments for diabetes mellitus type II: New perspectives regarding the possible role of calcium and cAMP interaction.

Diabetes mellitus (DM) is among the top ten causes of death worldwide. It is considered to be one of the major global epidemics of the 21st century, with a significant impact on public health budgets. DM is a metabolic disorder with multiple etiologies. Its pathophysiology is marked by dysfunction of pancreatic ß-cells which compromises the synthesis and secretion of insulin along with resistance to insulin action in peripheral tissues (muscle and adipose). Subjects presenting insulin resistance in DM type 2 often also exhibit increased insulin secretion and hyperinsulinemia. Insulin secretion is controlled by several factors such as nutrients, hormones, and neural factors. Exocytosis of insulin granules has, as its main stimulus, increased intracellular calcium ([Ca+2]i) and it is further amplified by cyclic AMP (cAMP). In the event of this hyperfunction, it is very common for ß-cells to go into exhaustion leading to failure or death. Several animal studies have demonstrated pleiotropic effects of L-type Ca2+ channel blockers (CCBs). In animal models of obesity and diabetes, treatment with CCBs promoted restoration of insulin secretion, glycemic control, and reduction of pancreatic ß-cell apoptosis. In addition, hypertensive individuals treated with CCBs presented a lower incidence of DM when compared with other antihypertensive agents. In this review, we propose that pharmacological manipulation of the Ca2+/cAMP interaction system could lead to important targets for pharmacological improvement of insulin secretion in DM type 2.

L-Arginine supplementation improves insulin sensitivity and beta cell function in the offspring of diabetic rats through AKT and PDX-1 activation.

Maternal hyperglycemia can result in defects in glucose metabolism and pancreatic ß-cell function in offspring. The purpose of this study was to evaluate the impact of maternal diabetes mellitus on pancreatic islets, muscle and adipose tissue of the offspring, with or without oral l-Arginine supplementation. The induction of diabetes was performed using streptozotocin (60mg/kg). Animals were studied at 3 months of age and treatment (sucrose or l-Arginine) was administered from weaning. We observed that l-Arg improved insulin sensitivity in the offspring of diabetic mothers (DA), reflected by higher insulin-induced phosphorylation of Akt in muscle and adipose tissue. Insulin resistance is associated with increased oxidative stress and the NADPH oxidase enzyme plays an important role. Our results showed that the augmented interaction of p47PHOX with gp91PHOX subunits of the enzyme in skeletal muscle tissue in the offspring of diabetic rats (DV) was abolished after l-Arg treatment in DA rats. Maternal diabetes caused alterations in the islet functionality of the offspring leading to increased insulin secretion at both low (2.8mM) and high (16.7mM) concentrations of glucose. l-Arg reverses this effect, suggesting that it may be an important modulator in the insulin secretory process. In addition it is possible that l-Arg exerts its effects directly onto essential molecules for the maintenance and survival of pancreatic islets, decreasing protein expression of p47PHOX while increasing Akt phosphorylation and PDX-1 expression. The mechanism by which l-Arg exerts its beneficial effects may involve nitric oxide bioavailability since treatment restored NO levels in the pancreas.