The interaction of central command and the exercise pressor reflex in mediating baroreflex resetting during exercise in humans Export

@article{expphysiol:91:79, abstract = {10.1113/expphysiol.2005.032110 Central command and the exercise pressor reflex can independently reset the carotid baroreflex (CBR) during exercise. The present investigation assessed the interactive relationship between these two neural mechanisms in mediating baroreflex resetting during exercise. Six men performed static leg exercise at 20\% maximal voluntary contraction under four conditions: control, no perturbation; neuromuscular blockade (NMB) induced by administration of the neuromuscular blocking agent Norcuron (central command activation); MAST, application of medical antishock trousers inflated to 100 mmHg (exercise pressor reflex activation); and Combo, NMB plus MAST (concomitant central command and exercise pressor reflex activation). With regard to CBR control of heart rate (HR), both NMB and Combo conditions resulted in a further resetting of the carotid\^{a}€“cardiac stimulus\^{a}€“response curve compared to control conditions, suggesting that CBR\^{a}€“HR resetting is predominately mediated by central command. In contrast, it appears that CBR control of blood pressure can be mediated by signals from either central command or the exercise pressor reflex, since both NMB and MAST conditions equally augmented the resetting of the carotid\^{a}€“vasomotor stimulus\^{a}€“response curve. With regard to the regulation of both HR and blood pressure, the extent of CBR resetting was greater during the Combo condition than during overactivation of either central command or the exercise pressor reflex alone. Therefore, we suggest that central command and the exercise pressor reflex interact such that signals from one input facilitate signals from the other, resulting in an enhanced resetting of the baroreflex during exercise.}, author = {Gallagher, Kevin M. and Fadel, Paul J. and Smith, Scott A. and Str\~{A}¸mstad, Morten and Ide, Kojiro and Secher, Niels H. and Raven, Peter B.}, citeulike-article-id = {444989}, citeulike-linkout-0 = {http://dx.doi.org/10.1113/expphysiol.2005.032110}, citeulike-linkout-1 = {http://ep.physoc.org/content/91/1/79.abstract}, citeulike-linkout-2 = {http://ep.physoc.org/content/91/1/79.full.pdf}, citeulike-linkout-3 = {http://www.ingentaconnect.com/content/bsc/eph/2006/00000091/00000001/art00009}, citeulike-linkout-4 = {http://view.ncbi.nlm.nih.gov/pubmed/16263799}, citeulike-linkout-5 = {http://www.hubmed.org/display.cgi?uids=16263799}, doi = {10.1113/expphysiol.2005.032110}, issn = {0958-0670}, journal = {Experimental Physiology}, keywords = {baro\_sensitivity, baroreflex, blood\_pressure}, month = {January}, number = {1}, pages = {79--87}, posted-at = {2009-10-16 20:23:49}, priority = {2}, publisher = {Blackwell Publishing}, title = {The interaction of central command and the exercise pressor reflex in mediating baroreflex resetting during exercise in humans}, url = {http://dx.doi.org/10.1113/expphysiol.2005.032110}, volume = {91}, year = {2006} }

TY - JOUR ID - expphysiol:91:79 L3 - citeulike-article-id:444989 N2 - 10.1113/expphysiol.2005.032110 Central command and the exercise pressor reflex can independently reset the carotid baroreflex (CBR) during exercise. The present investigation assessed the interactive relationship between these two neural mechanisms in mediating baroreflex resetting during exercise. Six men performed static leg exercise at 20% maximal voluntary contraction under four conditions: control, no perturbation; neuromuscular blockade (NMB) induced by administration of the neuromuscular blocking agent Norcuron (central command activation); MAST, application of medical antishock trousers inflated to 100 mmHg (exercise pressor reflex activation); and Combo, NMB plus MAST (concomitant central command and exercise pressor reflex activation). With regard to CBR control of heart rate (HR), both NMB and Combo conditions resulted in a further resetting of the carotid–cardiac stimulus–response curve compared to control conditions, suggesting that CBR–HR resetting is predominately mediated by central command. In contrast, it appears that CBR control of blood pressure can be mediated by signals from either central command or the exercise pressor reflex, since both NMB and MAST conditions equally augmented the resetting of the carotid–vasomotor stimulus–response curve. With regard to the regulation of both HR and blood pressure, the extent of CBR resetting was greater during the Combo condition than during overactivation of either central command or the exercise pressor reflex alone. Therefore, we suggest that central command and the exercise pressor reflex interact such that signals from one input facilitate signals from the other, resulting in an enhanced resetting of the baroreflex during exercise. IS - 1 JF - Experimental Physiology SN - 0958-0670 EP - 87 TI - The interaction of central command and the exercise pressor reflex in mediating baroreflex resetting during exercise in humans PB - Blackwell Publishing VL - 91 SP - 79 KW - baro_sensitivity KW - baroreflex KW - blood_pressure AU - Gallagher, Kevin AU - Fadel, Paul AU - Smith, Scott AU - Strømstad, Morten AU - Ide, Kojiro AU - Secher, Niels AU - Raven, Peter PY - 2006/01// UR - http://dx.doi.org/10.1113/expphysiol.2005.032110 ER -