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R Wadsworth

Publications and source records attributed to R Wadsworth.

3 recordsLinked to original sources

Age-associated changes in mesenteric arteries.

Vascular disease increases in incidence with age and is the commonest cause of morbidity and mortality among elderly people. Hypertension is associated with hypertrophy of the arterial media. This study was designed to investigate changes in arterial structure that may occur with age independent of blood pressure. Collapsed sections of human mesenteric arteries (external diameter 2-3 mm) were measured using a semi-automatic image analysis system. There was a nonlinear increase in both the wall/lumen area ratio and the relative intimal area with age. There were no significant relationships between blood pressure and either the wall/lumen ratio or the relative intimal area.

Adult

Contraction followed by relaxation in response to hypoxia in the sheep isolated middle cerebral artery.

In rings of sheep middle cerebral artery, precontracted with 5-hydroxytryptamine (5-HT) 10 microM, hypoxia (pO2 = 10 mm Hg) caused contraction and re-oxygenation caused a transient further relaxation. The hypoxic contraction was abolished and the re-oxygenation relaxation was reduced by removal of the endothelium. BW755C 20 microM reduced the hypoxic contraction and re-oxygenation relaxation. Haemolysate 1 microliter/ml and methylene blue 10 microM reduced the hypoxic contraction and re-oxygenation relaxation and enhanced the hypoxic relaxation phase. It is concluded that the endothelium of isolated rings of sheep middle cerebral artery releases vasoconstrictor substances during hypoxia and releases vasodilator substances during re-oxygenation.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz