Sudomotor modifications by acclimatization of stay in temperate Japan of Malaysian native tropical subjects.

Heat Acclimatization in Hot Summer for Ten Weeks Suppress the Sensitivity of Sweating in Response to Iontophoretically-administered Acetylcholine

“…The related finding of a depressed sensitivity of the sweat glands, following repeated ACh administration, supports this claim. Chen and Elizondo (1974) observed the depression of thermal sweating after repeated ACh iontophoresis, in support of our earlier data that showed that the suppression of the sweat gland response in a significant contributor to the suppression of sudomotor function in tropical natives Lee et al, , 2002Bae et al, 2006). In contrast to these observations, short-term heat acclimation increases the activity of the sweat glands.…”

“…The data were acquired for another 5 min to permit simultaneous observation of DIR and AXR (2) [sweating during 5 min post-iontophoresis] sweating. The data, including sweat onset-time, latent period for sweating after current loading, sweat volume for more then 5 min, area under the sweating curve, 0∼5 min for AXR (1) and 6∼ 11 min for AXR (2), and DIR, were used for the analysis (Lee et al, 2002(Lee et al, , 2004(Lee et al, , 2008.…”

“…The suppressed sweating in tropical natives (Matsumoto et al, 1993;Ogawa & Sugenoya, 1993;Lee et al, 1997Lee et al, , 2002Bae et al, 2006) provides the advantage of preserving body fluid and osmoregulation so that individuals can better sustain thermoregulation (Sawka & Coyle, 1999). The mechanisms responsible for the reduction of dripped sweat with tropical acclimatization, however, are unknown.…”

“…Although it is widely known that tropical natives maintain suppressed sweating during heat stress (Matsumoto et al, 1993;Ogawa et al, 1993; et , 2002, 2004, 2008Bae et al, 2006), the precise site and nature of the sweat suppression has not been fully established. Experimental evidence has previously shown that peripheral mechanisms play a predominant role, compared to the central nervous system, in the suppression or augmentation of sweating (Collins & Weiner, 1962;Fox et al, 1962;Ogawa et al, 1982).…”

Effect of the Heat-exposure on Peripheral Sudomotor Activity Including the Density of Active Sweat Glands and Single Sweat Gland Output

“…It is painless and there is no risk associated with the subcutaneous injection; it is a simple and convenient ion permeation method that can be used for evaluation. The results of QSART to acclimatized individuals over the long term have shown a reduction in the sweating response to stimuli [5,8,15,16] of injection of ACh in native residents that move from warm areas to tropical areas and lived there for 2∼12 years showed suppression of sweating sensitivity that depended on the extension of the period of acclimatization [6]. The sweating sensitivity increased based on the extension of the deacclimatization period [7].…”