Takenaka T, Inoue T, Kanno Y, Okada H, Hill CE, Suzuki H. Connexins 37 and 40 transduce purinergic signals mediating renal autoregulation. Am J Physiol Regul Integr Comp Physiol 294: R1–R11, 2008. First published October 10, 2007; doi:10.1152/ajpregu.00269.2007.—Our previous data indicated that various subtypes of connexin (Cx) were expressed in the juxtaglomerular apparatus. Experiments were p...

The upper limit of autoregulation of cerebral blood flow was studied in ten young baboons. Blood pressure was increased by infusing angiotensin, and cerebral blood flow was measured by the intracarotid 133 xenon injection method. Autoregulation was maintained until blood pressure was 30-40% above resting values. At this blood pressure level, cerebrovascular resistance reached a maximum. Any add...

Assessing noninvasively cerebral autoregulation, the protective mechanism of the brain to maintain constant cerebral blood flow despite changes in blood pressure, is challenging. Infants on life support system (ECMO) for cardiorespiratory failure are at risk of cerebral autoregulation impairment and consequent neurological problems. We measured oxyhaemoglobin concentration (HbO(2)) by multichan...

AIMS To examine whether dynamic cerebral autoregulation is acutely impaired during maximal voluntary apnoea in trained divers. METHODS Mean arterial pressure (MAP), cerebral blood flow-velocity (CBFV) and end-tidal partial pressures of O2 and CO2 (PETO2 and PETCO2) were measured in eleven trained, male apnoea divers (28 ± 2 yr; 182 ± 2 cm, 76 ± 7 kg) during maximal "dry" breath holding. Dynam...

46 Autoregulation of renal blood flow (RBF) is an essential function of the renal 47 microcirculation that has been previously shown to be blunted by excessive dietary salt. 48 Endogenous endothelin 1 (ET-1) is increased following a high salt (HS) diet and 49 contributes to the control of RBF but the differential effects of ET-1 on renal microvessel 50 autoregulation in response to HS remain to...

BACKGROUND AND PURPOSE Mx is an index of cerebrovascular autoregulation. It is calculated as the correlation coefficient between slow spontaneous fluctuations of cerebral perfusion pressure (cerebral perfusion pressure=arterial blood pressure-intracranial pressure) and cerebral blood flow velocity. Mx can be estimated noninvasively (nMxa) with the use of a finger plethysmograph arterial blood p...

BACKGROUND AND PURPOSE Recent studies have suggested that autoregulation of cerebral blood flow (CBF) is impaired after traumatic and ischemic brain injury. Given that the levels of superoxide anion (O2*-) are increased in these conditions, we postulate that O2*- contributes to the impairment of CBF autoregulation. METHODS CBF was monitored with laser Doppler flowmetry during increases in blo...

Cerebral Auwregulalion in Man • Autoregulation was tested by regional blood flow (rCBF) and cardiohemodynamic measurements before and after induced systemic arterial hypertension in 16 patients with varying neurological disorders. Hypertension was induced by increasing the arterial blood pressure by an intravenous infusion of Aramine. Seven (Group 1) of the patients had a mean increase in mean ...

The Brown Norway (BN) rat is normotensive and has an extended lifespan but is extremely sensitive to hypertension-induced renal injury. Relative impairment of autoregulation has been implicated in the progression of renal failure whereas absence of myogenic autoregulation is associated with early renal failure. Therefore, we tested the hypothesis that there is conditional failure of renal autor...

To test whether cerebral autoregulation is impaired in patients with neurally mediated syncope (NMS), we evaluated 15 normal subjects and 37 patients with recurrent NMS. Blood pressure (BP), heart rate, and cerebral blood velocity (CBV) (transcranial Doppler) were recorded at rest and during 80 degrees head-up tilt (HUT). Static cerebral autoregulation as assessed from the change in cerebrovasc...