TY - GEN
T1 - Physiological measurement of central vasoconstrictive tone and local cutaneous vasoconstrictive sensitivity for modeling purposes
AU - Kingma, B.R.M.
AU - Marken Lichtenbelt, van, W.D.
AU - Frijns, A.J.H.
AU - Saris, W.H.M.
AU - Steenhoven, van, A.A.
PY - 2008
Y1 - 2008
N2 - Currently many thermoregulatory models incorporate cutaneous perfusion, as it plays a major role in heat transport. The magnitude of perfusion is generally described as a function of temperature. Some physiological models, such as formulated by Stolwijk, Tanabe and Fiala, incorporate central tonus and local sensitivity explicitly. However, used perfusion control parameters have been estimated and are not based on physiological measurements. Therefore, their applicability might not be justified. In this research a method is proposed to measure central sympathetic vasoconstrictor tone and local cutaneous vasoconstrictor sensitivity. Together, the protocol was performed on males and females, young adults (18-28yr) and elderly (68-78yr) and on both glabrous and non-glabrous skin. Local cutaneous perfusion is measured by laser-Doppler flowmetry.
Through iontophoresis of Bretylium tosylate (10mM) sympathetic nerve terminals are blocked, such that local endogenous release of sympathetic neurotransmitters is abolished. Afterwards a superphysiological dose noradrenaline (2.5mM) is administered through iontophoresis. The reduction in perfusion is used as a measure for vasoconstrictor sensitivity at maximal vasoconstrictor tone. This is repeated over a range of local temperatures. Then the whole body is cooled and the decrease in perfusion at a non-bretylium site is measured. Combining perfusion and local sensitivity, vasoconstrictor tone is described as a function of temperature.
AB - Currently many thermoregulatory models incorporate cutaneous perfusion, as it plays a major role in heat transport. The magnitude of perfusion is generally described as a function of temperature. Some physiological models, such as formulated by Stolwijk, Tanabe and Fiala, incorporate central tonus and local sensitivity explicitly. However, used perfusion control parameters have been estimated and are not based on physiological measurements. Therefore, their applicability might not be justified. In this research a method is proposed to measure central sympathetic vasoconstrictor tone and local cutaneous vasoconstrictor sensitivity. Together, the protocol was performed on males and females, young adults (18-28yr) and elderly (68-78yr) and on both glabrous and non-glabrous skin. Local cutaneous perfusion is measured by laser-Doppler flowmetry.
Through iontophoresis of Bretylium tosylate (10mM) sympathetic nerve terminals are blocked, such that local endogenous release of sympathetic neurotransmitters is abolished. Afterwards a superphysiological dose noradrenaline (2.5mM) is administered through iontophoresis. The reduction in perfusion is used as a measure for vasoconstrictor sensitivity at maximal vasoconstrictor tone. This is repeated over a range of local temperatures. Then the whole body is cooled and the decrease in perfusion at a non-bretylium site is measured. Combining perfusion and local sensitivity, vasoconstrictor tone is described as a function of temperature.
U2 - 10.1159/000144991
DO - 10.1159/000144991
M3 - Conference contribution
T3 - Journal of vascular research
SP - 94
BT - Abstract of the 25th European Society for Microcirculation (ESM 2008) 26-29 August 2008, Budapest, Hungary
ER -