The goal was to estimate the link between blood pressure (BP) variability (BPV) and catecholamine BP surges. Mean femoral arterial BP (MAP), heart rate (HR) and ear lobe skin microcirculatory blood flow, by microphotoelectric plethysmography (MPPG), were recorded in conscious rabbits after 40 min carotid baroreceptor (CB) exposure to 350 mT static magnetic field (SMF), induced by Nd2-Fe14-B (n = 14) or sham magnets (n = 14), Fig. 1. Arterial baroreflex sensitivity (BRS) was estimated by HR and MAP responses to i.v. bolus inj. of phenylephrine (Ph) and nitroprusside (Ni), beat-to-beat BPV by MAP standard deviation (SD). SMF CB exposure significantly increased BRSNi (74.5 ± 17.8%, P < 0.001) and microcirculation (23.8% ± 11.0%, P = 0.039); decreased MAP (−5.7 ± 1.7%, P < 0.014), and Ph-induced MAP surge (−19.1%, P = 0.043), which is positively correlated with resting MAP (r = 0.342, P = 0.0383) and MAP SD (r = 0.383, P = 0.0194), and inversely with BRSPh (r = −0.47, P = 0.0156). CB magnetic stimulation increased Ni vasodilator effect, which acts as a nitric oxide (NO) donor, suggesting baroreflex to improve vessels sensitivity to NO-mediated dilation (impaired in diabetes), being a new physiology with BP buffering result. Enhanced BPV suggested to be a diagnostic tool for diabetics' susceptibility to morning surges of BP linked with major macrovascular events.
J. Gmitrov: None.
