Continuous Cardiac Monitoring around Atrial Fibrillation Ablation: Insights on Clinical Classifications and End Points.

Background: Atrial fibrillation (AF) is an arrhythmia that can be difficult to identify and classify with short-term monitoring. However, current standard of practice requires only short-term monitoring to determine AF classifications and identify symptom-arrhythmia correlations prior to AF ablation procedures. Insertable cardiac monitors (ICMs) offer continuous arrhythmia monitoring, which could lead to a more accurate measurement of AF burden than standard of practice.

Effects of Chronic Antagonism of Endocannabinoid-1 Receptors on Glucose Tolerance and Insulin Action in Skeletal Muscles of Lean and Obese Zucker Rats.

Background/aims: Antagonism of the endocannabinoid receptor-1 (CB1R) directly improves whole-body metabolic parameters of insulin resistance. The present investigation determined the effects of chronic CB1R antagonism on whole-body and skeletal-muscle insulin action in insulin-sensitive lean and insulin-resistant obese Zucker rats.

Methods: Animals were either fed ad libitum or in pairs, or treated with SR141716 (10 mg/kg i.

Oxidant stress-induced loss of IRS-1 and IRS-2 proteins in rat skeletal muscle: role of p38 MAPK.

Oxidative stress is characterized as an imbalance between the cellular production of oxidants and the cellular antioxidant defenses and contributes to the development of numerous cardiovascular and metabolic disorders, including hypertension and insulin resistance. The effects of prolonged oxidant stress in vitro on the insulin-dependent glucose transport system in mammalian skeletal muscle are not well understood. This study examined the in vitro effects of low-level oxidant stress (60-90 microM, H(2)O(2)) for 4 h on insulin-stimulated (5 mU/ml) glucose transport activity (2-deoxyglucose uptake) and on protein expression of critical insulin signaling factors (insulin receptor (IR), IR substrates IRS-1 and IRS-2, phosphatidylinositol 3-kinase, Akt, and glycogen synthase kinase-3 (GSK-3)) in isolated soleus muscle of lean Zucker rats.

Metabolic interactions of AGE inhibitor pyridoxamine and antioxidant alpha-lipoic acid following 22 weeks of treatment in obese Zucker rats.

Aims: The advanced glycation end product inhibitor pyridoxamine (PYR) and the antioxidant alpha-lipoic acid (LA) interact to ameliorate insulin resistance in obese Zucker rats following short-term (6-week) treatment. This study was designed to ascertain whether these unique interactive effects of PYR and LA remain manifest following longer-term (22-week) treatment.

Main Methods: Female obese Zucker rats received vehicle (OV), PYR (OP, 60 mg/kg body wt), racemic LA (rac-LA; OM, 92 mg/kg), the R-(+)-enantiomer of LA (R-LA; OR, 92 mg/kg), or combined treatments with PYR and rac-LA (OPM) or PYR and R-LA (OPR), daily for 22 weeks.

Interactions of the advanced glycation end product inhibitor pyridoxamine and the antioxidant alpha-lipoic acid on insulin resistance in the obese Zucker rat.

Oxidative stress and protein glycation can contribute to the development of insulin resistance and complications associated with type 2 diabetes mellitus. The antioxidant alpha-lipoic acid (ALA) reduces oxidative stress and the formation of advanced glycation end products (AGEs) and improves insulin sensitivity in skeletal muscle and liver. The AGE inhibitor pyridoxamine (PM) prevents irreversible protein glycation, thereby reducing various diabetic complications.

The high-fat-fed lean Zucker rat: a spontaneous isocaloric model of fat-induced insulin resistance associated with muscle GSK-3 overactivity.

High-fat feeding (HFF) is a well-accepted model for nutritionally-induced insulin resistance. The purpose of this investigation was to assess the metabolic responses of female lean Zucker rats provided regular chow (4% fat) or a high-fat chow (50% fat) for 15 wk. HFF rats spontaneously adjusted food intake so that daily caloric intake matched that of chow-fed (CF) controls.

Alterations in soleus muscle gene expression associated with a metabolic endpoint following exercise training by lean and obese Zucker rats.

Exercise training decreases insulin resistance and increases glucose tolerance in conditions of prediabetes and overt Type 2 diabetes. However, the adaptive responses in skeletal muscle at the molecular and genetic level for these effects of exercise training have not been clearly established in an animal model of prediabetes. The present study identifies alterations in muscle gene expression that occur with exercise training in prediabetic, insulin-resistant obese Zucker rats and insulin-sensitive lean Zucker rats and are associated with a well-defined metabolic outcome.