Elevations in Sweat Sodium Concentration Following Ischemia-Reperfusion Injury During Passive Heat Stress

Details

• Personal Author:
  Baker TB ; Freemas JA ; Hess HW ; Johnson BD ; Keeler JM ; Schlader ZJ ; Worley ML
• Description:
  Renal ischemia-reperfusion (I/R) injury results in damage to the renal tubules and causes impairments in sodium [Na+] reabsorption. Given the inability to conduct mechanistic renal I/R injury studies in vivo in humans, eccrine sweat glands have been proposed as a surrogate model given the anatomical and physiological similarities. We tested the hypothesis that sweat Na+ concentration is elevated following I/R injury during passive heat stress. We also tested the hypothesis that I/R injury during heat stress will impair cutaneous microvascular function. Fifteen young healthy adults completed approx. 160 min of passive heat stress using a water-perfused suit (50 degrees C). At 60 min of whole body heating, one upper arm was occluded for 20 min followed by a 20-min reperfusion. Sweat was collected from each forearm via an absorbent patch pre- and post-I/R. Following the 20-min reperfusion, cutaneous microvascular function was measured via local heating protocol. Cutaneous vascular conductance (CVC) was calculated as red blood cell flux/mean arterial pressure and normalized to CVC during local heating to 44 degrees C. Na+ concentration was log-transformed and data were reported as a mean change from pre-I/R (95% confidence interval). Changes in sweat sodium concentration from pre-I/R differed between arms post-I/R (experimental arm: +0.97 [+0.67 - 1.27] [LOG] Na+; control arm: +0.68 [+0.38 - 0.99] [LOG] Na+; P < 0.01). However, CVC during the local heating was not different between the experimental (80 +/- 10%max) and control arms (78 +/- 10%max; P = 0.59). In support of our hypothesis, Na+ concentration was elevated following I/R injury, but likely not accompanied by alterations in cutaneous microvascular function. [Description provided by NIOSH]
• Subjects:
  Heat Stress Disorders Hot Temperature Occupational Health Safety
• Keywords:
  Author Keywords: Ischemia-reperfusion Injury Heat Exposure Heat Stress Hot Environments Injuries Microvascular Function Physiological Factors Sodium Sweat Sweat Electrolytes Sweat Gland

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• ISSN:
  8750-7587
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Indiana ; New York ; OSHA Region 2 ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  134
• Issue:
  6
• NIOSHTIC Number:
  nn:20067361
• Citation:
  J Appl Physiol 2023 Jun; 134(6):1364-1375
• Contact Point Address:
  Zachary J. Schlader, Environmental Physiology Laboratory, Department of Kinesiology, Indiana University, Bloomington, IN, United States
• Email:
  zschlade@iu.edu
• Federal Fiscal Year:
  2023
• Performing Organization:
  Indiana University, Bloomington
• Peer Reviewed:
  True
• Start Date:
  20190901
• Source Full Name:
  Journal of Applied Physiology
• End Date:
  20240831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:c854585366de6ba11f3586157ddb59b82994463a43425564190b2fe1fecceab69c9884fddeec6c67d595fbedea033e409e40c35b4ce712efe4f966fdeb6e906a
• Download URL:
  https://stacks.cdc.gov/view/cdc/231427/cdc_231427_DS1.pdf
• File Type:
  [PDF - 1.63 MB ]