John A. Bevan

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Nitric oxide (NO), a potent vasodilator produced by endothelial cells, is thought to be the endothelium-dependent relaxing factor (EDRF) which mediates vascular relaxation in response to acetylcholine, bradykinin and substance P in many vascular beds. NO has been implicated in the regulation of blood pressure and regional blood flow, and also affects(More)
When examined by fluorescence microscopy the rabbit basilar artery contains a rich adrenergic-like plexus at the adventitiomedial junction. The fluorescence disappears upon chronic reserpinization and bilateral superior cervical ganglionectomy. Transmural stimulation of intramural nerves a results in a response which is predominantly constrictor but also(More)
A method is described for the direct recording of tension changes in the wall of blood vessels of 100 μm i.d. or less in vitro. Most vessels tested exhibited spontaneous rhythmic activity and responded tol-norepinephrine by an increase in tension. The response to transmural stimulation of the intramural nerves was variable.
A segment of the facial vein of the rabbit, that opposite the buccal cavity, responds to norepinephrine (NE) and opposite the buccal cavity, responds to norepinephrine (NE) and transmural nerve stimulation (TNS) by a brisk biphasic dilation. The dilation in response to both procedures is reveresed by prior exposure to propranolol (10(-6)M). Pretreatment(More)
Transmural nerve stimulation (TNS) with 0.3-msec pulses between 1 and 25 Hz dilated cat cerebral artery segments in the presence of active muscle tone. Maximum vasodilatation occurred at 8 Hz. The dilator response to exogenous acetylcholine, but not to TNS, was abolished by atropine. Neither physostigmine nor hemicholinium affected the dilator response to(More)
Responses of segments of basilar and middle cerebral arteries of eight human infants to activation of perivascular nerves and to vasoactive drugs were studied using a resistance artery myograph. The infants ages ranged from 23 wk of gestation to 34 postnatal days. Neurogenic vasoconstriction occurred in all segments and at 8 Hz was 12.7 ± 3.5% (11%) of(More)
The possibility of changes in the adrenergic innervation of blood vessels in experimental hypertension was investigated by measuring arterial norepinephrine content, neuronal uptake of norepinephrine, and the neurogenic contractile response in rabbits made hypertensive by partial constriction of the abdominal aorta proximal to the kidneys. Two to 3 weeks(More)
Autologous blood placed around the basilar artery caused angiographic narrowing with a biphasic time course. The first immediate phase was reversed by intraarterial papaverine; the second exhibited an increasing component of narrowing which was papaverine-resistant. In vitro studies showed that vessels became increasingly stiffer, less capable to develop(More)