Sucrose feeding reduces the ability of insulin to suppress glucose production and hepatic gluconeogenesis. The present study examined the effect of a high-sucrose diet on early insulin-signaling steps in the liver. Rats were provided a high-starch (STD, control diet) or high-sucrose diet (HSD) for 3 wk. On the day of study, overnight-fasted rats were anesthetized and injected with either saline...

A pathway sensitive to rapamycin, a selective inhibitor of mammalian target of rapamycin (mTOR), down-regulates effects of insulin such as activation of Akt (protein kinase B) via proteasomal degradation of insulin receptor substrate 1 (IRS-1). We report here that the pathway also plays an important role in insulin-induced subcellular redistribution of IRS-1 from the low-density microsomes (LDM...

S6K1 has emerged as a critical signaling component in the development of insulin resistance through phosphorylation and inhibition of IRS-1 function. This effect can be triggered directly by nutrients such as amino acids or by insulin through a homeostatic negative-feedback loop. However, the role of S6K1 in mediating IRS-1 phosphorylation in a physiological setting of nutrient overload is unre...

The effects of glucose, amino acids, pancreozymin-cholecystokinin, and tolbutamide upon the release of immunoreactive somatostatin (IRS) from the isolated perfused pancreas were studied. In seven experiments in which glucose was perfused either at a concentration of 100 or 350 mg/dl or at 25 mg/dl, IRS levels were significantly greater at the higher glucose concentrations. In three dose-respons...

Food choice and eating behavior affect health and longevity. Large-scale research efforts aim to understand the molecular and social/behavioral mechanisms of energy homeostasis, body weight, and food intake. Honey bees (Apis mellifera) could provide a model for these studies since individuals vary in food-related behavior and social factors can be controlled. Here, we examine a potential role o...

Insulin resistance is commonly observed both in overt diabetes and in individuals prone to, but not yet manifesting, diabetes. Hence the maintenance or restoration of insulin sensitivity may prevent the onset of this disease. We previously showed that homozygous disruption of insulin receptor substrate-1 (IRS-1) in mice resulted in insulin resistance but not diabetes. Here, we have explored the...

BACKGROUND/AIMS Insulin receptor (IR-alpha and IR-beta) is reduced in the kidney of insulin-resistant rodents. It is unknown if there are also reductions in insulin receptor substrate (IRS)-1 or if these effects are due to metabolic injury. Thereby, we hypothesized intrinsically high aerobic fitness would protect against high-fat diet (HFD)-induced reactive oxygen species (ROS) and IRS-1 degrad...

Little is known about the motivational background of smoking after a period of nicotine abstinence during pregnancy. The study examines the intention to resume smoking (IRS) in the post-partum period and its predictive value for smoking within 12 months post-partum. In a sample of 301 women recruited from obstetric wards who reported having stopped smoking during pregnancy, data on IRS, sociode...

One of the fundamental tasks in any distributed computing system is routing messages between pairs of nodes. An Interval Routing Scheme (IRS) is a space efficient way of routing messages in a network. The problem of characterizing graphs that support an IRS is a well-known problem and has been studied for some variants of IRS. It is natural to assume that the costs of links may vary over time (...

Patients with paroxysmal nocturnal hemoglobinuria (PNH) have a large clonal population of blood cells deriving from hematopoietic stem cells (HSCs) deficient in glycosylphosphatidylinositol (GPI)-anchored surface molecules. A current model postulates that PNH arises through negative selection against normal HSCs exerted by autoreactive T cells, whereas PNH HSCs escape damage. We have investigat...