Matthew A Tucker1,2, Aaron R Caldwell1, Cory L Butts1, Forrest B Robinson1, Stavros A Kavouras1, Brendon P McDermott1, Tyrone A Washington1, Ronna C Turner3, Matthew S Ganio4. 1. Department of Health, Human Performance, and Recreation, University of Arkansas, HPER 321-E, 155 Stadium Dr., Fayetteville, AR, 72701, USA. 2. Georgia Prevention Institute, Augusta University, Augusta, GA, USA. 3. Department of Rehabilitation, Human Resources, and Communication Disorders, University of Arkansas, Fayetteville, AR, USA. 4. Department of Health, Human Performance, and Recreation, University of Arkansas, HPER 321-E, 155 Stadium Dr., Fayetteville, AR, 72701, USA. msganio@uark.edu.
Abstract
INTRODUCTION: Obesity and hypohydration independently affect postsynaptic endothelial function, but it is unknown if hypohydration affects lean and obese individuals differently. PURPOSE: To examine the effect of hypohydration on postsynaptic cutaneous vasodilation and sweating in men with high and low adiposity (HI- and LO-BF, respectively). METHODS: Ten males with LO-BF and ten with HI-BF were instrumented for forearm microdialysis when euhydrated and hypohydrated. Changes in cutaneous vascular conductance (CVC) with intradermal infusion of sodium nitroprusside (SNP) and methacholine chloride (MCh) were assessed. Local sweat rate (LSR) was simultaneously assessed at the MCh site. At the end of the last dose, maximal CVC was elicited by delivering a maximal dose of SNP for 30 min to both sites with simultaneous local heating at the SNP site. The concentration of drug needed to elicit 50% of the maximal response (EC50) was compared between groups and hydration conditions. RESULTS: When euhydrated, EC50 of MCh-induced CVC was not different between LO- vs. HI-BF [- 3.04 ± 0.12 vs. - 2.98 ± 0.19 log (MCh) M, P = 0.841]. EC50 of SNP-induced CVC was higher in euhydrated HI- vs. LO-BF (- 1.74 ± 0.17 vs. - 2.13 ± 0.06 log (SNP) M, P = 0.034). Within each group, hydration status did not change MCh- or SNP-induced CVC (P > 0.05). LSR was not different between groups or hydration condition (P > 0.05). CONCLUSIONS: These data suggest reduced sensitivity of endothelium-independent vasodilation in individuals with high adiposity when euhydrated. However, hypohydration does not affect cutaneous vasodilation or local sweat rate differently between individuals with low or high adiposity.
INTRODUCTION: Obesity and hypohydration independently affect postsynaptic endothelial function, but it is unknown if hypohydration affects lean and obese individuals differently. PURPOSE: To examine the effect of hypohydration on postsynaptic cutaneous vasodilation and sweating in men with high and low adiposity (HI- and LO-BF, respectively). METHODS: Ten males with LO-BF and ten with HI-BF were instrumented for forearm microdialysis when euhydrated and hypohydrated. Changes in cutaneous vascular conductance (CVC) with intradermal infusion of sodium nitroprusside (SNP) and methacholine chloride (MCh) were assessed. Local sweat rate (LSR) was simultaneously assessed at the MCh site. At the end of the last dose, maximal CVC was elicited by delivering a maximal dose of SNP for 30 min to both sites with simultaneous local heating at the SNP site. The concentration of drug needed to elicit 50% of the maximal response (EC50) was compared between groups and hydration conditions. RESULTS: When euhydrated, EC50 of MCh-induced CVC was not different between LO- vs. HI-BF [- 3.04 ± 0.12 vs. - 2.98 ± 0.19 log (MCh) M, P = 0.841]. EC50 of SNP-induced CVC was higher in euhydrated HI- vs. LO-BF (- 1.74 ± 0.17 vs. - 2.13 ± 0.06 log (SNP) M, P = 0.034). Within each group, hydration status did not change MCh- or SNP-induced CVC (P > 0.05). LSR was not different between groups or hydration condition (P > 0.05). CONCLUSIONS: These data suggest reduced sensitivity of endothelium-independent vasodilation in individuals with high adiposity when euhydrated. However, hypohydration does not affect cutaneous vasodilation or local sweat rate differently between individuals with low or high adiposity.
Authors: Scott L Davis; Manabu Shibasaki; David A Low; Jian Cui; David M Keller; Gary F Purdue; John L Hunt; Brett D Arnoldo; Karen J Kowalske; Craig G Crandall Journal: J Burn Care Res Date: 2007 May-Jun Impact factor: 1.845
Authors: Matthew A Tucker; Ashley Six; Nicole E Moyen; Alf Z Satterfield; Matthew S Ganio Journal: Am J Physiol Regul Integr Comp Physiol Date: 2017-02-15 Impact factor: 3.619
Authors: Scott L Davis; Manabu Shibasaki; David A Low; Jian Cui; David M Keller; Jonathan E Wingo; Gary F Purdue; John L Hunt; Brett D Arnoldo; Karen J Kowalske; Craig G Crandall Journal: J Burn Care Res Date: 2009 Jul-Aug Impact factor: 1.845