Low-dose ouabain administration increases Na⁺,K⁺-ATPase activity and reduces cardiac force development in rats.

Background: Ouabain is a digitalis compound that inhibits the Na(+),K(+)-ATPase (NKA) activity inducing increment in cardiac force. However, this effect seems to be dose dependent. At low concentration, ouabain can induce an increase of NKA activity.

Ouabain induces nitric oxide release by a PI3K/Akt-dependent pathway in isolated aortic rings from rats with heart failure.

Background: Ouabain occurs in nanomolar concentrations in myocardial infarction and heart failure (HF). However, the effects of ouabain in vascular function in HF conditions were not investigated yet. Therefore, we analyzed the effects of acute administration of 3 nM ouabain in isolated aortic rings from rats with HF 4 weeks after myocardial infarction.

Low-dose chronic lead exposure increases systolic arterial pressure and vascular reactivity of rat aortas.

Chronic lead exposure induces hypertension affecting endothelial function. We investigated whether low-concentration lead exposure alters blood pressure and vascular reactivity, focusing on the roles of NO, oxidative stress, cyclooxygenase-derived vasoconstrictor prostanoids, and the local angiotensin-renin system. Aortic rings from 3-month-old Wistar rats were treated daily with lead acetate (first dose 4mg/100g, subsequent doses 0.

Post-weaning protein malnutrition increases blood pressure and induces endothelial dysfunctions in rats.

Malnutrition during critical periods in early life may increase the subsequent risk of hypertension and metabolic diseases in adulthood, but the underlying mechanisms are still unclear. We aimed to evaluate the effects of post-weaning protein malnutrition on blood pressure and vascular reactivity in aortic rings (conductance artery) and isolated-perfused tail arteries (resistance artery) from control (fed with Labina®) and post-weaning protein malnutrition rats (offspring that received a diet with low protein content for three months). Systolic and diastolic blood pressure and heart rate increased in the post-weaning protein malnutrition rats.

Soybean oil increases SERCA2a expression and left ventricular contractility in rats without change in arterial blood pressure.

Background: Our aim was to evaluate the effects of soybean oil treatment for 15 days on arterial and ventricular pressure, myocardial mechanics and proteins involved in calcium handling.

Methods: Wistar rats were divided in two groups receiving 100 microL of soybean oil (SB) or saline (CT) i.m.

Chronic ouabain treatment enhances cardiac myosin ATPase activity in rats.

1. Chronic ouabain administration increases blood pressure and produces a positive inotropic effect. However, the temporal changes capable of affecting both arterial and ventricular pressures and myosin ATPase activity during the induced hypertension have not been determined.

Small doses of mercury increase arterial pressure reactivity to phenylephrine in rats.

Mercury reduces cardiac contractility and arterial pressure at micromolar concentrations. We investigated the actions of 680ng/kg HgCl(2) on arterial pressure, heart rate (HR) and on the pressor reactivity to phenylephrine (PHE) in rats before and 1h after HgCl(2) administration and after hexametonium, verapamil and tempol treatments. HgCl(2) increased baseline systolic (SAP) and diastolic pressure (DAP) and HR, sensitivity (pD(2)) and maximal response (E(max)) to PHE pressor reactivity.