Effects of endotoxaemia on protein metabolism in rat fast-twitch skeletal muscle and myocardium.

Background: It is unclear if the rat myocardium undergoes the same rapid reductions in protein content that are classically observed in fast-twitch skeletal muscle during endotoxaemia.

Methodology/principal Findings: To investigate this further, and to determine if there is any divergence in the response of skeletal muscle and myocardium in the mechanisms that are thought to be largely responsible for eliciting changes in protein content, Sprague Dawley rats were implanted with vascular catheters and administered lipopolysaccharide (LPS; 150 microg kg(-1) h(-1)) intravenously for 2 h, 6 h or 24 h (saline administered control animals were also included), after which the extensor digitorum longus (EDL) and myocardium were removed under terminal anaesthesia. The protein-to-DNA ratio, a marker of protein content, was significantly reduced in the EDL following 24 h LPS administration (23%; P<0.

Regional heterogeneity in the haemodynamic responses to urotensin II infusion in relation to UT receptor localisation.

The aim of the study was to measure regional haemodynamic responses to 6 h infusions of human urotensin II (hUII), to identify possible mediators of the effects observed, and to relate the findings to the distribution of urotensin II receptors (UT receptors). Male, Sprague-Dawley rats had pulsed Doppler flow probes and intravascular catheters implanted for measurement of regional haemodynamics in the conscious, freely moving state. Infusions of saline (0.

Mesenteric vasoconstriction and hindquarters vasodilatation accompany the pressor actions of exendin-4 in conscious rats.

The hemodynamic effects of the glucagon-like peptide-1 (GLP-1) receptor agonist, exendin-4, and putative underlying mechanisms were assessed in conscious male Sprague-Dawley rats. At a dose of 25 ng kg(-1) i.v.

Reduced baroreflex sensitivity is associated with increased vascular calcification and arterial stiffness.

Introduction: Vascular calcification is a critical determinant of cardiovascular morbidity and mortality in chronic haemodialysis (HD) patients. The pathophysiology underlying this observation remains obscure. Baroreceptor sensitivity (BRS) is important in the maintenance of an appropriate cardiovascular status both at rest and under the physiological stress of HD.

Bolus injection of human UII in conscious rats evokes a biphasic haemodynamic response.

A biphasic cardiovascular response to bolus i.v. injection of human urotensin II (hUII, 3 nmol kg(-1)) in conscious, male, Sprague-Dawley (SD) rats was identified and underlying mechanisms were explored.

Regional hemodynamic actions of selective corticotropin-releasing factor type 2 receptor ligands in conscious rats.

In conscious male Sprague-Dawley rats, we compared regional hemodynamic actions of the selective corticotropin-releasing factor type 2 (CRF(2)) receptor ligands human and mouse urocortin 2 (hUCN2 and mUCN2, respectively) with those of CRF. Bolus i.v.

Regional hemodynamic effects of the N-(2-benzoylphenyl)-L-tyrosine peroxisome proliferator-activated receptor-gamma ligand, GI 262570 [(S)-2-(2-benzoylphenylamino)-3-[4-[2-(5-methyl-2-phenyl-2-oxazol-4-yl)ethoxy]phenyl]propionic acid], in conscious rats.

This study provides novel data on the regional hemodynamic effects of the peroxisome proliferator-activated receptor-gamma activator, GI 262570 [(S)-2-(2-benzoylphenylamino)-3-[4-[2-(5-methyl-2-phenyl-2-oxazol-4-yl)ethoxy]phenyl]propionic acid], in conscious, male Sprague-Dawley rats. Administration of GI 262570 twice daily for 4 days caused a slowly developing, modest fall in mean arterial blood pressure, associated with a progressive, hyperemic hindquarters vasodilatation, but with no consistent changes in renal or mesenteric hemodynamics. The hindquarters vasodilator effect of GI 262570 was not inhibited by the beta2-adrenoceptor antagonist, ICI 118551 ((+/-)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl) amino]-2-butanol hydrochloride), and was still apparent in the presence of the alpha-adrenoceptor antagonist, phentolamine.

Haemodynamic effects of the selective phosphodiesterase 5 inhibitor, UK-357,903, in conscious SHR.

1. Regional haemodynamic responses to a continuous, 4-day infusion of the selective phosphodiesterase type 5 inhibitor, UK-357,903 (0.133 or 1.

Acute cardiovascular effects of sibutramine in conscious rats.

Sibutramine is a serotonin and norepinephrine reuptake inhibitor, used in the treatment of obesity. In this study, cardiovascular effects of sibutramine (0.9, 3, or 9 mg kg(-1) i.

Comparative regional haemodynamic effects of the nitric oxide synthase inhibitors, S-methyl-L-thiocitrulline and L-NAME, in conscious rats.

1. The regional haemodynamic effects of the putative nNOS inhibitor, S-methyl-L-thiocitrulline (SMTC), were compared with those of the nonselective NOS inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), in conscious, male Sprague-Dawley rats. 2.

Fostering orphan receptors: an indispensable role for integrative, in vivo, haemodynamic studies.

The assessment of cardiovascular effects of well-recognised ligands for their known receptors can produce misleading results if measurements are restricted to blood pressure and heart rate in anaesthetised animals. Therefore, we propose that the most reliable delineation of any role for a particular ligand-receptor system in cardiovascular regulation can only be achieved by determination of the detailed haemodynamic effects of manipulating the system in vivo, in the absence of anaesthesia. This approach is powerful because, firstly, differences between in vitro and in vivo effects, possibly attributable to disparities between receptor genotype and receptor phenotype, are highlighted; and secondly, regional heterogeneity of cardiovascular effects, possibly in the absence of changes in systemic arterial blood pressure, can be detected.