Relationship between the Duration of Stay in Japan of Malaysian Subjects and the Suppression of Sweat Gland Sensitivity by lontophoretically Applied Acetylcholine
| Autor: | Saat, Mohamed, Lee, Jeong-Beom, Matsumoto, Takaaki, Kosaka, Mitsuo, Ohwatari, Nobu, Motomura, Katsuaki, Kaneda, Eiko, Taimura, Akihiro, Yamauchi, Masaki |
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| Jazyk: | angličtina |
| Rok vydání: | 1999 |
| Předmět: | |
| Zdroj: | Acta medica Nagasakiensia. 44(3-4):49-54 |
| ISSN: | 0001-6055 |
| Popis: | Tropical African and Thai Subjects regulate core temperature with less amount of sweat against heat compared to temperate Japanese subjects. Reduced sweating in tropical subjects was attributed to suppression of both central and peripheral sudomotor mechanisms. The objective of the study is to compare the local sweating response activated by acetycholine (ACh) applied iontophoretically among the Malaysians (n=12) of varying duration of stay in Japan. Based on their length of stay, Malaysian subjects were divided into 2 groups, MS (n=6) with a duration of stay of 3 to 15 months and ML (n=6) with 27 to 60 months. ACh, the primary transmitter for sudomotor innervation, was iontophoretically administered on the forearm. Sweating response elicited directly (DIR) and indirectly via axon reflex (AXR) were evaluated by quantitative sudomotor axon reflex test. Although the sweat onset time was tend to reduce with longer duration of stay among Malaysian subjects, there was no significant difference among the two groups. AXR (1), sweat volume elicited by axon reflex for 0-5 min was 0.96ﾂｱ0.11 mg/cm2 in MS and 1.40ﾂｱ0.23 mg/cm2 in ML. AXR(2), that for 6-11 min, was 1.09ﾂｱ0.13 mg/cm2 and 1.45ﾂｱ0.20 mg/cm2. DIR, sweat volume directly induced by ACh for 6-11 min, was 3.40ﾂｱ0.18 mg/cm2 and 3.96ﾂｱ0. 24 mg/cm2 in MS and ML , respectively. A slight positive correlation between DIR and the duration of stay in Japan was observed in Malaysian subjects, though not significant (p=0.14). From these results, suppressed neuroglandular response to ACh was confirmed in Malaysians. It is suggested that long-term heat-acclimatization acquired in tropical subjects may decay after immigration to temperate area. Acta medica Nagasakiensia. 1999, 44(3-4), p.49-54 |
| Databáze: | OpenAIRE |
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