Four Lethal MAO Errors You May End Up Making

Given that the brachial artery vasodilatation appeared to be temporally associated with increased forearm blood flow (Simmons et al. 2011), we hypothesized that elevated conduit artery shear stress caused by increased limb blood flow contributes to brachial artery dilatation during leg exercise. To test this hypothesis, in a within-subject design, we determined whether recapitulation of cycling-induced brachial artery shear rate with forearm heating would elicit comparable profiles and magnitudes of brachial artery vasodilatation to those observed during cycling. We selected forearm heating because this is a stimulus to increase blood flow through the brachial artery in a controlled MAO manner without altering muscle metabolism (Davis et al. 2006) or mean arterial pressure (Pyke et al. 2008b). Moreover, forearm heating is known to produce brachial artery dilatation that is shear stress dependent (Pyke et al. 2004, 2008a,b); that is, when the increase in brachial artery shear rate induced by forearm heating is prevented (maintained at basal levels), forearm heating does not alter brachial artery diameter. Therefore, matching of cycling-induced brachial artery shear rate via forearm heating provides SP600125 in vitro a unique experimental model to determine what portion of brachial artery dilatation observed during leg exercise is mediated by increased shear. Twelve healthy men with a mean age of 28 �� 2 years, height of 179 �� 2 cm, weight of 78 �� 3 kg and body mass index of 24.4 �� 0.8 kg m?2 (means �� SEM) were recruited for voluntary participation in the study. All subjects were free of any recognized cardiovascular, pulmonary, metabolic or neurological disease and were non-obese (body mass index C59 wnt Health Sciences Institutional Review Board and carried out in accordance with the guidelines of the Declaration of Helsinki. On experimental days, subjects were instructed to abstain from food for 4 h prior to the study and to avoid alcohol, caffeine and strenuous physical activity for 12 h. Heart rate was measured via a lead II electrocardiogram (ECG; Quinton Q710, Bothell, WA, USA). Arterial blood pressure was measured on the left brachial artery using an automated sphygmomanometer equipped with a microphone for the detection of Korotkoff sounds (Tango+; Suntech Medical Instruments, Raleigh, NC, USA). This method of blood pressure measurement has been previously validated for use during dynamic exercise (Cameron et al. 2004). Brachial artery diameter and velocity were measured using duplex Doppler ultrasound as previously described (Simmons et al. 2011).