Embryonic ventricular diastolic and systolic function was evaluated during normal ejection (coupled) and during acute ventricular outflow tract occlusion (uncoupled) in the stage 21 chick embryo. We simultaneously measured ventricular pressure with a servo-null system and ventricular dimensions using video microscopy. Experimental protocols included 1) baseline recording followed by acute conot...

OBJECTIVES Peroxynitrite (ONOO(-)) mediates in part both ischemia-reperfusion and pro-inflammatory cytokine-induced injury to the heart. As oxidants like ONOO(-) are known to activate matrix metalloproteinases (MMPs), we examined whether they play a role in the detrimental action of ONOO(-) in isolated perfused rat hearts. METHODS Hearts were isolated from Sprague-Dawley rats and perfused ret...

UDP-glucuronosyltransferase is expressed in the proximal convoluted tubular cells of rat kidney. Kidney perfusion with a Krebs-Henseleit buffer containing 1-naphthol was performed to estimate the dynamics and disposition of the glucuronide conjugate formed in the epithelial cells of the renal tubules. When 1-naphthol was injected into the renal artery, and the perfusate from the renal vein was ...

Elevated glucose level and low pH have been shown to increase red blood cell (RBC) rigidity. This increased rigidity has been proposed as one factor which mediates the tumor blood flow (TBF) reduction during hyperglycemia by (a) causing RBC entrapment and hence increasing geometric resistance and (b) increasing viscous resistance to blood flow. However, due to the inability to measure these res...

An isolated perfused lung (IPL) preparation was used to investigate the influence of acute environmental stress on lung substrate metabolism. The IPL apparatus consists of four perfusion flasks housed in a temperature-controlled Lucite box with a circulation fan. Lungs are ventilated by a positive pressure ventilation pump. The ventilation is arranged so that the lung can be ventilated with any...

Hearts of wild-type and cytosolic muscle creatine kinase (M-CK)-knockout mice were perfused with Krebs-Henseleit buffer containing 10 mM glucose and 5 mM pyruvate and studied during pacing at 400 and 600 beats/min and during K+ arrest. Phosphocreatine (PCr) and ATP concentrations in M-CK-deficient hearts were not significantly different from those in wild-type hearts. With the use of31P NMR sat...

BACKGROUND Shear stress induces coronary dilatation via production of nitric oxide (NO). This should involve the endothelial glycocalyx (EG). A greater effect was expected of albumin versus hydroxyethyl starch (HES) perfusion, because albumin seals coronary leaks more effectively than HES in an EG-dependent way. METHODS Isolated hearts (guinea pigs) were perfused at constant pressure with Kre...

Under acute hypoxic conditions, the muscle oxygen uptake (mV˙O2) during exercise is reduced by the restriction in oxygen-supplied volume to the mitochondria within the peripheral tissue. This suggests the existence of a factor restricting the mV˙O2 under hypoxic conditions at the peripheral tissue level. Therefore, this study set out to test the hypothesis that the restriction in mV˙O2 is regul...

BACKGROUND The recent introduction of operations on a warm heart has prompted clinical reports on the usefulness of continuous blood cardioplegia, but no in-depth basic evaluation of continuous cardioplegia has been done. The cardioprotective effects of magnesium (Mg) and calcium (Ca) in continuous warm hyperkalemic crystalloid cardioplegic solutions were investigated in an isolated rat heart m...

We investigated the effects of phytoestrogen on global myocardial ischemia-reperfusion injury in five groups of female rats. A high-phytoestrogen group (HPE) was ovariectomized (Ovx) and fed a diet containing soybean protein and a high-isoflavone soy extract. Another Ovx group of rats was fed the same diet as the HPE group but treated with the estrogen receptor blocker ICI-182,780 (HPE + ICI). ...