Analysis of thermoregulatory and pyretic responses in heat-and cold-acclimation

点击翻译按钮获取中文摘要

This investigation was designed to clarify the central and peripheral mechanism of thermal acclimation from the concept of hypothalamic and extra-hypothalamic thermosensitivity of CNS in human and animal.I. Pyrogenic and poor heat loss responses in pika (Whistle rabbit): Pika,s better heat conservation ability thought to be due to its higher metabolic rate. poor heat dissipation through the weak thermal panting and smaller ear surface area. Further, it was reported that pika is markedly senitive to narcotics, but it responds poorly to i.p. administration of LPS pyrogen. However, in the present study, it was clear that pika can elicit fever with i.v. LPS pyrogen but heat loss mechanism differs from that of albino rabbit, that is, the poor evaporative heat loss ability in pika is most probable due to smallness of the ear as a heat radiator and lack of thermal panting.II. Changes in cerabral blood flow (CBF) due to theraml acclimation; the change in CBF is closely associated with air temp … More erature as well as thermoregulatory parameters. Not only the less increase in CBF due to heating but also less decrease due to cooling was observed in the heat-acclimated rabbit compared to those of control rabbit, and similar results were obtained in the cold acclimated rabbit. The reduction of gain in thermoregulatory responses occurred during general heating and cooling as well as pyrogen administration in both heat- and cold- acclimated rabbits, so the reduced change in CBF of brain in the process of the thermal acclimation might cause habituation phenomenon of thermal responses to heat and cold stimulation.III. Analysis of heat-exercise cross adaptation in hot dry sauna; the heat acclimation procedure is capable of inducing heat acclimation to the sportsmen as well as the tropical subjects who may be closely related to inherent consititutional characteristic and his acquired heat tolerance, and the results of the spotsmen may be due to the enhanced ability of heat production and evaporative heat loss response owing to larger cross adaptability by co-operation of heat and exercise load.In this investigation, to clarity the effect of thyroid hormone on thermal sweating, thermal sweating in patients with hyperthyroidism and hypothyroidism was determined by using of capacitance hygrometer-sweat capture capsule method. However, further reseaches are necessary to clarity the effects of various hormones on thermal sweating and the action site of hormones on sweating mechanism. Less