In adult twins, visceral fat accumulation depends more on exceeding sex-specific adiposity thresholds than on genetics.

Objective: We recently reported sex-specific percent body fat (%BF) thresholds (males=23%, females=38%) above which, visceral adipose tissue (VAT) significantly increases. Using monozygotic (MZ) and dizygotic (DZ) twins, we examined the influence of genetics on regional fat distribution measured by dual-energy X-ray absorptiometry, above and below these sex-specific thresholds for VAT accumulation.

Methods: Fifty-eight twin pairs (44 MZ, 14 DZ) were recruited from the University of Washington Twin Registry.

Cardiomyocyte mitochondrial oxidative stress and cytoskeletal breakdown in the heart with a primary volume overload.

Left ventricular (LV) volume overload (VO) results in cardiomyocyte oxidative stress and mitochondrial dysfunction. Because mitochondria are both a source and target of ROS, we hypothesized that the mitochondrially targeted antioxidant mitoubiquinone (MitoQ) will improve cardiomyocyte damage and LV dysfunction in VO. Isolated cardiomyocytes from Sprague-Dawley rats were exposed to stretch in vitro and VO of aortocaval fistula (ACF) in vivo.

Increased sarcolipin expression and adrenergic drive in humans with preserved left ventricular ejection fraction and chronic isolated mitral regurgitation.

Background: There is currently no therapy proven to attenuate left ventricular (LV) dilatation and dysfunction in volume overload induced by isolated mitral regurgitation (MR). To better understand molecular signatures underlying isolated MR, we performed LV gene expression analyses and overlaid regulated genes into ingenuity pathway analysis in patients with isolated MR.

Methods And Results: Gene arrays from LV tissue of 35 patients, taken at the time of surgical repair for isolated MR, were compared with 13 normal controls.

Xanthine oxidase inhibition preserves left ventricular systolic but not diastolic function in cardiac volume overload.

Xanthine oxidase (XO) is increased in human and rat left ventricular (LV) myocytes with volume overload (VO) of mitral regurgitation and aortocaval fistula (ACF). In the setting of increased ATP demand, XO-mediated ROS can decrease mitochondrial respiration and contractile function. Thus, we tested the hypothesis that XO inhibition improves cardiomyocyte bioenergetics and LV function in chronic ACF in the rat.

Methamphetamine and core temperature in the rat: ambient temperature, dose, and the effect of a D2 receptor blocker.

Rationale: Methamphetamine (METH) induces hyperthermia in warm and hypothermia in cool environments. Our first goal was to further study the role of ambient temperature in METH's effect on core temperature in rats. Previously, these effects were primarily demonstrated in high doses; we extended this investigation to the low-dose range (1 mg/kg METH).