抄録
Seasonal variations have been reported in a wide range of physiological parameters, including components of the neuroendocrine and immune system.In the present study we investigated the seasonal changes on hormonal and autonomic nervous systems. 8 volunteers were subjected for the experiment at four times of the year–around the vernal and autumnal equinoxes and the summer and winter solstices. Seasonal changes in the thermoregulatory responses are assessed by measuring core and skin temperatures, sweat rate and blood flow during immersion of the leg in hot water (mild heat at 40oC to 42oC) for 30 min. The following parameters were analyzed: metabolites of catecholamine (VMA, HVA, 5-HIAA), angiotensin II, aldosterone, plasma renin activity, ADH, cortisol, ACTH, GH, leptin, IL-6. Tympanic temperature increased significantly in winter during water immersion of 42oC compared with the same condition in spring and summer. Sweating rate was significantly higher and sweating more quickly appeared in summer season compared with winter or spring. Concentration of ADH and angiotensin II was significantly higher in summer compared with winter and spring. Concentration of IL-6 was significantly lower in spring and summer compared with winter. Concentration of ACTH and cortisol was significantly higher in summer. The results of this study demonstrated statistically significant seasonal changes in ADH, angiotensin II, VMA, IL-6, and core body temperature and sweat rate. [J Physiol Sci. 2008;58 Suppl:S60]
