Objective: Increasing evidence suggests that endothelial nitric oxide (NO) deficit and baroreflex dysfunction are associated with a variety of cardiovascular conditions, ranging from arterial hypertension to stroke and coronary heart disease, importantly appearing even in preclinical stages of the disease. To test the hypothesis that the arterial baroreflex has a modulatory effect on NO-dependent vasodilation, sodium nitroprusside (SNP), a spontaneous NO-donor, vasodilatory effect was studied in conjunction with sinocarotid baroreceptor magnetic stimulation and potential implementation in NO deficiency states.
Methods: Mean femoral artery blood pressure (MAP), heart rate (HR) and ear lobe skin microcirculatory blood flow, measured by a microphotoelectric plethysmogram (MPPG), were simultaneously recorded in conscious rabbits before and after 40-min sinocarotid baroreceptor exposure to 350 mT static magnetic field (SMF), generated by Nd2-Fe4-B alloy (n=8) or sham magnets (n=8, controls). Arterial baroreflex sensitivity (BRS) was measured by changes in HR and MAP (ΔHR/ΔMAP) after intravenous bolus injections of SNP and phenylephrine.
Results: The vasodilatory effect of SNP significantly increased after SMF sinocarotid baroreceptor exposure (MPPGbeforeSMF: 2.57 ± 0.81 V vs. MPPGafterSMF: 7.82 ± 1.61 V, p<0.0001) and positively correlated with significant increase in BRS (r=0.51, p=0.01).
Conclusions: Baroreflex-mediated increment in vessel sensitivity to NO is suggested to be a new mechanism in baroreflex physiology with potential implementation in cardiovascular conditions where NO deficit and autonomic dysfunction increase the risk of morbidity and mortality substantially.
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http://dx.doi.org/10.1016/j.mvr.2014.11.004 | DOI Listing |
Microvasc Res
March 2015
National Institute of Public Health, Department of Environmental Health, Tokyo 108, Japan(1); Pro Vitae Hospital, Diabetology Clinic, Nemocnicna 33, Gelnica 05601, Slovak Republic(2); Krompachy Hospital, Agel SK Inc., Diabetology Clinic, Banicka stvrt 1, Krompachy, 05642, Slovak Republic(3). Electronic address:
Objective: Increasing evidence suggests that endothelial nitric oxide (NO) deficit and baroreflex dysfunction are associated with a variety of cardiovascular conditions, ranging from arterial hypertension to stroke and coronary heart disease, importantly appearing even in preclinical stages of the disease. To test the hypothesis that the arterial baroreflex has a modulatory effect on NO-dependent vasodilation, sodium nitroprusside (SNP), a spontaneous NO-donor, vasodilatory effect was studied in conjunction with sinocarotid baroreceptor magnetic stimulation and potential implementation in NO deficiency states.
Methods: Mean femoral artery blood pressure (MAP), heart rate (HR) and ear lobe skin microcirculatory blood flow, measured by a microphotoelectric plethysmogram (MPPG), were simultaneously recorded in conscious rabbits before and after 40-min sinocarotid baroreceptor exposure to 350 mT static magnetic field (SMF), generated by Nd2-Fe4-B alloy (n=8) or sham magnets (n=8, controls).
Electromagn Biol Med
December 2013
Department of Environmental Health, The National Institute of Public Health, Tokyo , Japan.
We compared in conscious rabbits, sedated using pentobarbital intravenous (i.v.) infusion (5 mg kg(- 1) h(- 1)), the effect of a static magnetic field (SMF), generated by Nd2-Fe14-B magnets, on microcirculation during its 40 min local exposure to the microvascular network in cutaneous tissue [20 sham exposure and 20 SMF (0.
View Article and Find Full Text PDFInt J Radiat Biol
February 2010
Department of Environmental Health, The National Institute of Public Health, Tokyo, Japan.
Purpose: We compared the effect of static magnetic field (SMF) and verapamil, a potent vascular calcium channel blocking agent, on sudden elevation in blood pressure in conjunction with arterial baroreflex sensitivity (BRS) and microcirculation.
Materials And Methods: Forty-four experiments were performed on conscious rabbits sedated using pentobarbital intravenous (i.v.
The vaso-renal arterial hypertension was produced in in the "two kidneys-one clip" model in experiments on Wistar male rats. This procedure was performed both in rats with intact mechanoreceptor zones of large vessels and the rats with destroyed baroreceptors. The date obtained indicate that in rats with cutting of "buffer" nerves the arterial hypertension after clipping renal artery occurred in all rats while in rats with intact sino-carotid and aortal nerves arterial hypertension developed only in 39% of the animals.
View Article and Find Full Text PDFRadiat Environ Biophys
August 2007
Department of Environmental Health, National Institute of Public Health, Tokyo, Japan.
Increasing evidence suggests that time-varying and static magnetic fields in the environment might affect the cardiovascular system. To explore the underlying physiology, the effect of static magnetic fields (SMFs) on the carotid baroreflex control of microcirculation was studied. Twenty-four hemodynamic monitorings were performed in rabbits sedated by pentobarbital infusion (5 mg/kg/h) during experiments that lasted 120 min.
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