Metformin Prevents Low-dose Isoproterenol-induced Cardiac Dilatation and Systolic Dysfunction in Male Sprague Dawley Rats.

Myocardial metabolic abnormalities are well-recognized alterations in chronic heart failure, effects that may contribute to progressive cardiac dysfunction. However, whether metabolic alterations in-part mediate their deleterious effects by modifying the chronic impact of excess low-dose sympathetic stimulation on cardiac chamber dilatation is uncertain. We therefore aimed to determine the effect of metformin administration on cardiac function and mitochondrial architectural changes in a rat model of chronic sympathetic-induced left ventricular (LV) remodeling and systolic dysfunction [daily subcutaneous isoproterenol (ISO) injection at a low dose of 0.

Dietary-induced obesity hastens the progression from concentric cardiac hypertrophy to pump dysfunction in spontaneously hypertensive rats.

We explored whether dietary-induced obesity hastens the transition from concentric left ventricular (LV) hypertrophy to pump dysfunction in spontaneously hypertensive rats (SHRs) and the mechanisms thereof. After feeding rats a diet for 4 to 5 months, obesity was induced in SHRs and Wistar-Kyoto (WKY) control rats. Obesity was not associated with abnormal blood glucose control (glycosylated hemoglobin) or with increases in systolic blood pressure.

The relationship between blood pressure and left ventricular mass index depends on an excess adiposity.

Aim: To determine whether blood pressure (BP)-LVM relationships depend in-part on the influence of an excess adiposity and whether this translates into a greater effect of hypertension on LVM in obese as compared with lean people.

Methods: In 399 randomly recruited participants from a general population with a high prevalence of excess adiposity ( approximately 68%), we assessed whether the relationships between conventional blood pressure (BP) and LVM indexed for height (LVMI) (determined from echocardiography) are influenced by adiposity. We confirmed these outcomes using 24-h ambulatory measurements in 297 participants; and carotid-femoral pulse wave velocity (PWV) (applanation tonometry) in 328 participants and from plasma leptin concentrations, we assessed whether leptin could mediate this effect.

Gender-specific brachial artery blood pressure-independent relationship between pulse wave velocity and left ventricular mass index in a group of African ancestry.

Aim: As it is uncertain whether arterial stiffness is related to left ventricular mass and left ventricle mean wall thickness independent of blood pressure measured at the brachial artery, we aimed to ascertain this effect in never-treated participants with a high prevalence of risk factors for large artery dysfunction.

Methods: The conventional and ambulatory blood pressure-independent relations between indices of large artery function and either left ventricular mass or mean wall thickness were determined in 309 never-treated randomly recruited South Africans of African ancestry with prevalent risk factors for large artery changes [24% were hypertensive, 63% were overweight/obese, and 17% had diabetes mellitus or abnormal blood glucose control (glycosylated hemoglobin A1c > 6.1%)].

The association of waist circumference with ambulatory blood pressure is independent of alternative adiposity indices.

Aim: The relationship between waist circumference (WC) and conventional blood pressure (BP) is independent of other clinical indices of adiposity. As ambulatory BP may offer more prognostic information than conventional BP, we aimed to identify whether indices of central adiposity are associated with ambulatory BP independent of other indices of adiposity.

Methods: The relationship between indices of adiposity [WC, waist-to-hip ratio, body mass index (BMI) or skin-fold thickness] and ambulatory or conventional BP was determined in 300 randomly selected individuals of African descent living in an urban developing community in South Africa.

Upstream stimulatory factor 1 transactivates the human gene promoter of the cardiac isoform of acetyl-CoA carboxylase.

E-box cis-elements act as binding sites for upstream stimulatory factors (USFs), putative glucose-responsive transcriptional modulators. Since four E-boxes were identified on the human ACCbeta promoter, we hypothesized that USF1 induces ACCbeta expression in a glucose-dependent manner. Here, murine cardiac ACCbeta expression was significantly increased in response to high carbohydrate re-feeding after fasting.

H-89, a non-specific inhibitor of protein kinase A, promotes post-ischemic cardiac contractile recovery and reduces infarct size.

Myocardial ischemia is associated with increased production of cyclic adenosine monophosphate (cAMP), with potentially deleterious effects. We hypothesized that the ischemia-induced activation of cAMP-dependent protein kinase A (PKA), could beneficially be inhibited by a PKA-inhibitor N-(2-[p-bromocinnamylamino]ethyl)-5-isoquinoline-sulfonamide (H-89). H-89 when given to isolated perfused rat hearts before 30 minutes of global ischemia-reperfusion improved postischemic function and decreased infarct size.