(An) experimental study on sweat secretion during 2 hours of heat exposure
땀은 체온이나 기온이 상승함에 따라 분비가 증가되며 체온조절에 큰 역할을 담당하고
땀분비의 이상이 있는 사람은 열사병(heat pyrexia)의 위험이 크며(Ferris등, 1938: Ma
cQuaide, 1944: Schwartz 및 Itoh, 1956: Knochel, 1974) 땀분비가 과도히 일어난 후에는
열자극이나 약물자극에 대한 한선의 땀분비가 감소되며 땀의 Na**+농도는 올라가는 한선
피로 현상이 나타나며 열사병의 중요한 원인이 된다(Thaysen 및 Schwartz, 1955: Sibinga
및 Barbero, 1961: Peter 및 Wyndham, 1966).
Thaysen 및 Schwartz(1955), Sibinga 및 Barbero(1961), Peter 및 Wyndham(1966)등의
여러 학자들이 한선피로현상에 대해 보고하였으나 땀분비 지속시간이 2∼6시간으로 다양
하며 이때 땀의 Na**+농도에 대한 연구는 많지 않았다.
저자는 정상한국인 9명을 대상으로 하여 2시간 동안 건구온도 46℃, 습구온도 37℃되는
Environ-Room에서 땀을 분비시키고 땀분비율, 한공의 수, 땀의 Na**+농도, 피부 및 직장
온도, 심박동수의 변화를 관찰하여 다음과 같은 결론을 얻었다.
1. 땀분비량은 우측전박에서 30∼45분에 40.0±4.91㎝**2로 최고에 달하였고 이후 점차
감소하여 105∼120분에는 24.9±4.2㎎/4.91㎝**2이었다. 좌측전박 및 등에서도 같은 경
땀분비율이 좌우측 전박은 차이가 없으나 등은 전박보다 약 2배 높았다.
2. 단위면적당 한공의 수는 10분, 1시간에는 비슷하나 2시간 후에는 감소되는 경향을
보였으나 통계학적 의의는 없었다. 등에서는 전박보다 한선의 수가 적었다.
3. 땀의 Na**+농도는 개인차가 컸으며 등에서 전박보다 높았다. 실험대상자 가각에서
첫시간보다 둘째시간에 Na**+농도가 높았다.
4. 피부온도는 첫 30분에 급격히 상승한 반면 직장온도는 서서히 증가하여 2시간 후에
는 38.92±0.06℃로 되었다.
5. 심박동수는 땀분비중 계속 증가하여 2시간 후에는 52.6±3.7 beats/min의 증가를 나
Sweating is an essential physiologic phenomenon regulating human body temperature
and in case of high environmental temperature and high relative humidity henat
dissipation depends solely upon perspiration.
According to Knochel(1974), a number of disorters with impairment of sweat
production as well as congestive heart failure, chronic disabling disease, and
inadequate acclimatization have been associated with a higher incidence of heat
stroke (heat Phrexia).
After intense prolonged sweating, sweating, decreases with concurrent rise in
Na**+ concentration of the sweat, this is the phenomenon of sweat gland fatigue
which is the one of the important causes of heat pyrexia (Thaysen and Schwartz,
1955; Sibinga and Barbero, 1961; Peter and Wyndham, 1966).
But according to investigators, difference exist concerning the duration of
continuous profuse sweating from two to six hours and concerning the decrease in
sweat amount during intense prolonged stimulation of sweat glands.
The purpose of this investigation was to evaluate the sweat secretion to the
number of sweat pores, sodium concertration of sweat, skin and rectal temperatures,
ana pulse rates in adult males during 2 hours of heat exposure.
Materials and Methods
Subjects were nine healthy adult males.
The experiment was performed in October(early autumn). An Environ-Room (Dry bulb
46℃, Wet bulb 37℃;p Lab-Line Insc. INt. Melrose Park, Ⅲ.) was used for sweat
Induction for 2 hours. Sweat was collected on both forearms and back every 15
minutes with the sweat collectors designed by Sato and Dobson(1969)(mg/4.91㎝**2).
Sweat pores were counted three times with bromphenolblue papers (Herrmann etc.,
1951) during the experiment; i,e., 10 minutes, 1 hours, and 2 hours after
beginning of heat exposure.
Sodium concertration of sweat were measured with a flame photometer(mEq/ℓ). Skin
temperatures were measured with a telethermometer and rectal temperatures with an
indwelling thermistor probe every 15 minutes for 2 hours. Pulse rates were courted
at the wrist every 15 minutes for 2 hours.
Summary and Conclusion :
1. During the experimental sweat secretions on the right forearm until 45 min. to
40.0mg/4.91㎝**2/15 min (30-45 min), but decreased thereafter to
24.9mg/4.91㎝**2/15 min (105-120 min) after 2 hours of heat exposure. Lt. forearm
and back showed similar results.
Sweat amounts from the back are about twice those of the right forearm but there
were no differences in the amounts of sweat between the right and left forearms.
2. The number of sweat pores was 87.9/㎝**2 on the Rt. forearm and 71.O/㎝**2 on
the back at 10 minutes and then decreased to 79.2/㎝**2 on the Rt. forearm and
70.4/㎝**2 on the back at 2 hours after heat exposure, but there was no statistical
In spite of the higher sweat rates on the back, the number of sweat pores was
smaller here than on the Rt. forearm.
3. Na**+ concentration of sweat showed great individual variations ranging from
32.6mEq/ℓ to 134.0mEq/ℓ. This concentration was higher on the back than on the
Rt. forearm in 7 of 9 subjects during the 1st hour of the experiment. Na**+
concentration of sweat were higher in the 2nd hour than in the 1st hour and the
increases were 14.9mEq/ℓ on the Rt. forearm and 12.3mEq/ℓ on the back.
4. Skin temperatures markedly increased in the first 30 minutes from 33.33℃ to
36.85℃ and then increased slowly to 37.97℃ at the end of the experiment in all
subjects, but rectal temperatures increased slowly from 37.43℃ to 38.92℃ at the
end of 2 hours. The rate of increase in rectal temperature was a little greater
during the second hour than during the first hour of the experiment.
5. Heart rate increased steadily during the experiment, and there was an
increment of 52.6±3.7 beats/min after 2 hours of heat exposure.