Control of skin blood flow in the neutral zone of human body temperature regulation.

In humans, matching of heat loss and heat production in the "neutral" zone, defined operationally in terms of a range of skin temperatures (Tsk), is accomplished by regulation of skin blood flow (SkBF). Our studies were designed to reveal the characteristics of control of SkBF [from measurements of forearm blood flow (FBF)] in this zone. We controlled the temperature of water sprayed on most of the body of supine men and women at 33 or 35 degrees C in a square-wave pattern (15 min at each temperature) or a step pattern (60 min at 33 degrees C separated by short periods at 35 degrees C). FBF followed Tsk (0.5 ml.min-1.degrees C-1). Esophageal temperature changed approximately 0.11 degrees C with each 2 degrees C change in Tsk, falling with Tsk increase and vice versa. Little influence on FBF, < 0.1 ml.min-1.100 ml-1. degrees C-1, was observed when only the forearm was sprayed with 33 and 35 degrees C water. We conclude that SkBF control in the 33-35 degree C range of Tsk is dominated by the feedforward reflex influence of Tsk on SkBF. The reflex response overcompensates for the effect of Tsk on thermal balance in the neutral zone, so that equilibrium core temperature has an inverse relationship to Tsk.

[1]  J. Hatcher,et al.  Temperature and blood flow in the forearm of the Eskimo. , 1953, Journal of applied physiology.

[2]  E. Nadel,et al.  Importance of skin temperature in the regulation of sweating. , 1971, Journal of applied physiology.

[3]  A. C. Burton,et al.  The application of the theory of heat flow to the study of energy metabolism. , 1934 .

[4]  W F Taylor,et al.  Effect of high local temperature on reflex cutaneous vasodilation. , 1984, Journal of applied physiology: respiratory, environmental and exercise physiology.

[5]  A. B. Craig,et al.  Thermal regulation during water immersion. , 1966, Journal of applied physiology.

[6]  R. J. Whitney,et al.  The measurement of volume changes in human limbs , 1953, The Journal of physiology.

[7]  J D HARDY,et al.  Physiology of temperature regulation. , 1960, Physiological reviews.

[8]  O G Edholm,et al.  Temperature and blood flow in the human forearm , 1946, The Journal of physiology.

[9]  J. Johnson,et al.  Nonthermoregulatory control of human skin blood flow. , 1986, Journal of applied physiology.

[10]  O G EDHOLM,et al.  The blood flow in skin and muscle of the human forearm , 1955, The Journal of physiology.

[11]  J M Detry,et al.  Skin and muscle components of forearm blood flow in directly heated resting man. , 1972, Journal of applied physiology.

[12]  E. F. Bois.  Heat Loss from the Human Body: Harvey Lecture, December 15, 1938. , 1939, Bulletin of the New York Academy of Medicine.

[13]  O G Edholm,et al.  The effect of temperature on blood flow and deep temperature in the human forearm , 1943, The Journal of physiology.

[14]  G. Brengelmann,et al.  Reproducibility of the vascular response to heating in human skin. , 1994, Journal of applied physiology.

[15]  L. Rowell,et al.  Altered control of skin blood flow at high skin and core temperatures. , 1975, Journal of applied physiology.

[16]  L. Rowell,et al.  Modification of the skin blood flow-body temperature relationship by upright exercise. , 1974, Journal of applied physiology.

[17]  M L Collis,et al.  Thermoregulatory heat production in man: prediction equation based on skin and core temperatures. , 1977, Journal of applied physiology: respiratory, environmental and exercise physiology.

[18]  T. Mccaffrey,et al.  Role of skin temperature in the control of sweating. , 1979, Journal of applied physiology: respiratory, environmental and exercise physiology.

[19]  E. Nadel,et al.  Forearm blood flow during body temperature transients produced by leg exercise. , 1975, Journal of applied physiology.

[20]  C B Wenger,et al.  Regulation of the cutaneous circulation. , 1986, Federation proceedings.

[21]  James D. Hardy,et al.  Basal Metabolism, Radiation, Convection and Vaporization at Temperatures of 22 to 35°C. Six Figures , 1938 .

[22]  L. Rowell,et al.  Interactions between local and reflex influences on human forearm skin blood flow. , 1976, Journal of applied physiology.

[23]  S. Sagawa,et al.  Esophageal and tympanic temperature responses to core blood temperature changes during hyperthermia. , 1986, Journal of applied physiology.

[24]  G. Brengelmann,et al.  Electrocardiographic verification of esophageal temperature probe position. , 1979, Journal of applied physiology: respiratory, environmental and exercise physiology.

[25]  R. Shanks,et al.  The relationship between the onset of sweating and vasodilatation in the forearm during body heating , 1962, The Journal of physiology.

[26]  A. C. Burton,et al.  A STUDY OF THE AVERAGE TEMPERATURE OF THE TISSUES, OF THE EXCHANGES OF HEAT AND VASOMOTOR RESPONSES IN MAN BY MEANS OF A BATH CALORIMETER , 1936 .

[27]  L. Rowell,et al.  Cardiovascular aspects of human thermoregulation. , 1983, Circulation research.

[28]  C R Wyss,et al.  Control of skin blood flow, sweating, and heart rate: role of skin vs. core temperature. , 1974, Journal of applied physiology.