Barry Alexander

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Previous designs of isolated rat liver perfusion circuits used for toxicological investigations are often expensive, cumbersome, or traumatic in relation to hepatic biocompatibility following extended perfusion times. A new, miniaturized circuit that incorporates a novel design of organ bath, to maintain a buoyant preparation, and a high-efficiency(More)
1. Adenosine has been shown to be responsible for the hyperaemic response of the hepatic artery to portal vein occlusion (the hepatic arterial 'buffer response'). 2. The effect of adenosine receptor blockade and of adenosine uptake inhibition on the hepatic arterial response to portal vein occlusion was investigated in three groups of anaesthetized dogs. 3.(More)
BACKGROUND/AIMS Hepatotoxin-induced rat models of liver cirrhosis are limited by the wide heterogeneity of cirrhosis produced. The present study developed a modified, reliable, and reproducible technique by which hepatic and systemic responses to thioacetamide during induction of cirrhosis were monitored by weekly weight changes. METHODS Male Wistar rats(More)
This study describes the localization of endothelin-1-, vasopressin- and substance P-like immunoreactivity in a subpopulation of endothelial cells of the basilar and posterior communicating arteries of the (i) normal rabbit brains and (ii) rabbit brains perfused with a perfluorocarbon emulsion (PFC). Following perfusion with the PFC at increased flow the(More)
BACKGROUND Portal hypertension is associated with gross haemodynamic disturbances characterised by high cardiac output, low peripheral vascular resistance, increased splanchnic blood flow, and portal systemic shunting. AIMS To study the relationship between intrahepatic portal systemic shunts and microsphere induced portal hypertension in the rat liver.(More)
Intrahepatic shunts regulate portal venous pressure during periods of acute portal hypertension when the transhepatic portal resistance is momentarily increased in the normal rat liver in vivo. Hepatic arterial inflow may also increase the transhepatic portal resistance and activate intrahepatic shunts. In the present study, the transhepatic portal(More)
The locations of the vascular resistance sites which regulate vascular tone in the hepatic arterial and portal venous vasculatures of the rat liver were identified using a new, in vitro, dual-perfused liver preparation. Twelve livers of male Wistar rats were perfused via the hepatic artery and portal vein at fixed flow and at physiological pressure.(More)
The role of nitric oxide in the modulation of hepatic arterial vascular reactivity was investigated in an isolated dual-perfused rat liver preparation. Twelve male Wistar rats (200-250 g) were anaesthetized with sodium pentobarbitone (60 mg kg-1 i.p.). The livers were then excised and perfused in vitro through hepatic arterial and portal venous cannulae at(More)
The cerebral vasculature of five anaesthetised rabbits was perfused with a perfluorocarbon emulsion via the internal carotid arteries, and the effluent from the jugular veins analysed for ATP, substance P (SP), endothelin (ET) and arginine vasopressin (AVP). Viability of the preparation was monitored periodically by the electrocorticogram, oxygen uptake,(More)
The physiological role of nitric oxide (NO) in portal venous and hepatic arterial haemodynamics in the rat in vivo during healthy and diseased conditions remains unclear. The present study determined the physiological role of nitric oxide in hepatic haemodynamics in the rat in vivo during healthy conditions as a basis for future pharmacological work. Male(More)