Obese Zucker rats (OZR) are mildly hypertensive with an apparently elevated sympathetic vasomotor tone compared with lean Zucker rats (LZR). Studies have also suggested enhanced adrenergic pressor reactivity in OZR but assumed comparable baroreflexes, or blood volume-to-body weight ratio, to LZR. In 15-wk-old OZR and LZR, we measured plasma volume and vascular reactivity to norepinephrine (NE) ...

BACKGROUND HIV infection and treatment with highly active antiretroviral therapy (HAART) including HIV protease inhibitor ritonavir (RTV) have been associated with endothelial dysfunction and cardiovascular disease including pulmonary arterial hypertension. The objective of this study was to determine if nordihydroguaiaretic acid (NDGA), a natural herbal antioxidant found in the creosote bush L...

Parkinson's disease (PD), multiple system atrophy (MSA) and pure autonomic failure (PAF) are neurodegenerative disorders frequently associated with orthostatic hypotension and syncope, though with different underlying mechanisms. Cerebral hemodynamic responses in these three neurodegenerative diseases are still incompletely studied and it is possible that they would be differentially affected. ...

When D,L-propranolol, 100 mg/kg/day, was added to the drinking water of spontaneously hypertensive rats (SHR), systolic pressures measured with the tail-cuff method fell significantly within 1 month and were almost the same as those in normotensive controls (KNR) by the end of 3 months. This antihypertensive effect was later confirmed by direct recording of phasic aortic pressures from indwelli...

BACKGROUND Recent investigations have demonstrated the ability of vascular endothelial growth factor (VEGF) to augment the development of collateral arteries in vivo. In vitro studies have suggested that the use of VEGF also improves the endothelium-dependent relaxation of collaterals at the microvascular level. The purpose of this study was to determine in vivo the extent to which vasomotor re...

BACKGROUND AND PURPOSE There is experimental evidence that L-arginine restores diminished CO2 reactivity after mild traumatic brain injury in rats. This effect is believed to be mediated by L-arginine-derived nitric oxide, which is a permissive substrate for CO2 reactivity. To clarify whether these findings can be transferred to the clinical situation and have beneficial effects in patients, we...

BACKGROUND AND PURPOSE Estimation of dynamic cerebral autoregulation from spontaneous fluctuations of arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV) is an attractive monitoring option for cerebral hemodynamic impairment. We evaluated the correlation coefficient index method in patients with severe obstructive carotid disease and compared it with transfer function analysis...