Submitted on August 9, 2004
Accepted on December 27, 2004
Pilocarpine-induced sweat gland function in individuals with multiple sclerosis
Scott L. Davis1, Thad E. Wilson2, Jamie M. Vener1, Craig G. Crandall3, Jack H. Petajan4, and Andrea T. White1*
1 Department of Exercise & Sport Science, University of Utah, Salt Lake City, UT, USA
2 Department of Medicine, Penn State University College of Medicine, Hershey, PA, USA
3 Presbyterian Hospital of Dallas, Institute for Exercise & Environmental Medicine, Dallas, TX, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
4 Department of Neurology, University of Utah School of Medicine, Salt Lake City, UT, USA
* To whom correspondence should be addressed. E-mail: Andrea.White{at}health.utah.edu.
This investigation tested the hypothesis that cholinergic sweat function of individuals with multiple sclerosis (MS; n=10) is diminished relative to matched healthy control subjects (CON, n=10). In addition, cholinergic sweat function was determined prior to and following 15 weeks of aerobic training in a subgroup of individuals with MS (MS-EX, n=7). Cholinergic sweating responses were assessed via pilocarpine iontophoresis on ventral forearm skin. A collection disc placed over the stimulated area collected sweat for 15 minutes. Sweat rate (SR) was calculated by dividing sweat collector volume by collection area and time. Iodine-treated paper was applied to the
stimulated area to measure number of activated sweat glands (ASG). Sweat gland output (SGO)was calculated by dividing SR by density of glands under the collector. Sweat gland function was determined in MS-EX to test the hypothesis that exercise training would increase sweating
responses. No differences in ASG were observed between MS and CON. SR and SGO in MS (0.18 ± 0.08 mg.cm-2.min-1; 1.74 ± 0.79 µg.gld-1.min-1) were significantly lower (P 
0.05) than
CON (0.27 ± 0.10 mg.cm-2.min-1; 2.43 ± 0.69 µg.gld-1.min-1) respectively. Aerobic exercise training significantly (P 0.05) increased VO2peak in MS-EX (1.86 ± 0.75 L.min-1 vs. 2.10 ± 0.67 L.min-1) with no changes in ASG, SR, and SGO. Sweat gland function in individuals with MS is impaired relative to healthy controls. Fifteen weeks of aerobic training did not increase stimulated sweating responses in individuals with MS. Diminished peripheral sweating responses may be a
consequence of impairments in autonomic control of sudomotor function.
