Adrenal Cortex and Work in the Heat

The Effects of Heat Adaptation on Physiology, Perception and Exercise Performance in the Heat: A Meta-Analysis

“…A more dilute sweat can be more readily evaporated due to the resultant reduction in cutaneous water vapour pressure [9]. Increasing aldosterone concentrations can increase the amount of sodium reabsorbed by the sweat glands [117] and so the reductions observed in sodium and chloride concentrations in sweat lost may be, at least in part, due to the HA-induced increases in resting aldosterone concentrations reported in most [24,44,45,55,56,104,111] but not all [22,24,66,81] HA investigations. Resting aldosterone and arginine vasopressin concentrations show large levels of inter-investigation variability and while HA had a small positive effect on resting aldosterone concentrations [22,24,44,45,55,56,66,81,104,111] no such effect was observed for resting arginine vasopressin concentrations [44,55,56,81].…”

Body Fluid Balance During Heat Stress in Humans

“…They noted similar salt conservation responses in unacclimatized subjects following administration of desoxycorticosterone (DCA). However, Robinson et al (195) and Moreira et al (161) could not demonstrate any improvement in heat acclimatization in subjects pretreated with DCA. In addition, Bass and colleagues (23,26) found no elevation in markers of adrenal cortical activity, such as in 17-ketosteroids, over the course of heat acclimatization.…”

“…Many early studies viewed the inability of adrenal cortical hormones to alter sweat composition as evidence against their role in heat acclimatization (141,161,195). However, many of these studies administered aldosterone just prior to thermal stress, while the latency of action of treatment is more on the order of 18-24 h (196).…”

Salt Losses of Men Working in Hot Environments

“…Current hypothesis favours the involvement of the adrenal cortex, and this has received support from experiments by Conn and others (1946) and Robinson (1949) who have shown that desoxycorticosterone acetate reduces the chloride of general body sweat, as suggested earlier by Laddell (1945) and Moreira, Johnson, Forbes, and Consolazio-(1945) using arm bag samples. Conn (1949 a and b) believes that the adrenal cortex activity is mediated through the adreno-corticotrophic hormone of the pituitary.…”