We determined the effect of plasma obtained from rats treated with DOCA-salt for 6 and 28 days on sodium pump activity, measured as ouabain-sensitive Rb+ uptake in tail arteries from these rats. The effect of an electrolytic lesion in the area of the anteroventral third cerebral ventricle (AV3V) before DOCA-salt treatment was investigated in relation to the ability of plasma to inhibit vascular...

We investigated the effects of estrogen on global myocardial ischemia-reperfusion injury in rats that were ovariectomized (Ovx), sham-operated, or ovariectomized and then given 17beta-estradiol (E(2)beta) supplementation (Ovx+E(2)beta). Hearts were excised, cannulated, perfused with and then immersed in chilled (4 degrees C) cardioplegia solution for 30 min, and then retrogradely perfused with ...

Endothelium-dependent relaxation of the aorta was assessed in JCR:LA-corpulent rats, which are hyperphagous, hyperlipidemic, hyperinsulinemic, and obese and spontaneously develop atherosclerotic disease and myocardial lesions. The findings in corpulent rats (6 months of age) were compared with those in age-and sex-matched lean rats. Aortic rings were prepared and mounted in Krebs-Henseleit buff...

The purpose of these studies was to test whether O2 tension influences cardiotoxicity due to doxorubicin. Isolated hearts were perfused by the method of Langendorff at constant pressure with Krebs-Henseleit buffer saturated with 5% CO2 and either 95% or 20% O2. Toxicity due to doxorubicin was evaluated from changes in heart rate and from uptake of trypan blue by nonviable nuclei. Heart rate was...

The pore-forming hemolysin of Escherichia coli (HlyA), an important virulence factor in extraintestinal E. coli infections, causes thromboxane generation and related vasoconstriction in perfused rabbit lungs (Seeger, W., H. Walter, N. Suttorp, M. Muhly, and S. Bhakdi. 1989. J. Clin. Invest. 84:220). We investigated the influence of pulmonary vascular "priming" with endotoxin on the responsivene...

Autoxidation of para-aminophenol (PAP) has been proposed to account for the selective nephrotoxicity of this compound. However, other studies suggest that hepatic metabolites of PAP rather than the parent compound may be responsible for renal damage. These studies were designed to investigate PAP metabolism in isolated hepatocytes. We synthesized several proposed metabolites for analysis by HPL...

We examined the effect of endothelin-3 (ET-3) at a high dose (pressor dose) and a low dose (non-pressor dose) in rat perfused kidney (PK), since ET-3 has recently been reported to exert a vasodilator action especially at a low dose. Kidneys were perfused with Krebs-Henseleit buffer at a fixed flow rate (6 ml/min) in situ. After collection of the renal venous effluent and urine for 20 min, vehic...

Leonotis leonurus (L. leonurus) R. Br. (Lamiaceae) is used by healers in South Africa. The present study was conducted to determine if the L. leonurus effect on isolated rat heart is due to ionic changes in the perfusion fluid. Isolated rat hearts were perfused after Langendorff at 74 mmHg with modified Krebs–Henseleit buffer (K-H) and three test solutions: Ll (2 mg/ml dried crude aqueous leaf ...

GSEs (grape seed extracts) which contain polyphenolic compounds cause an endothelium-dependent relaxation of blood vessels. The aim of the present study was to examine the mechanisms involved in this response. A well-characterized GSE was applied to rabbit aortic rings suspended in organ baths containing Krebs-Henseleit buffer maintained at 37 degrees C. In aortic rings pre-contacted with norad...

Neural retina from most species contains 3,4- dihydroxyphenylethylamine (dopamine) receptors coupled to stimulation of adenylate cyclase activity. It has been demonstrated that release of dopamine from its neurons and subsequent occupation of dopamine receptors is increased by light. In this study, we have shown that adenylate cyclase activity in bovine retina is highly responsive to the endoge...