Effects of bromocriptine on sweat gland function during heat acclimatization

Area of Science:

• Physiology
• Endocrinology
• Environmental Medicine

Background:

• Heat acclimatization involves physiological adaptations to improve thermoregulation.
• Hormonal regulation, including aldosterone and prolactin, plays a role in sweat gland function.
• The specific impact of prolactin on sweat gland adaptation during heat exposure requires further elucidation.

Purpose of the Study:

• To investigate the role of aldosterone and prolactin in sweat gland function during heat acclimatization.
• To determine the effect of bromocriptine, a dopamine agonist, on prolactin levels and sweat gland response.
• To examine the relationship between hormonal changes and electrolyte concentration in sweat during prolonged heat exposure.

Main Methods:

• Two groups of male subjects underwent 10 days of cycle ergometer exercise in a controlled hot environment (39°C, 30% RH).
• One group received a placebo (control), while the other received bromocriptine to suppress prolactin.
• Total body washdown was used to measure sweat electrolyte concentrations; plasma aldosterone and prolactin levels were monitored.

Main Results:

• Prolactin levels increased during exercise in the control group but were suppressed by bromocriptine.
• Plasma aldosterone increased in both groups, with no significant differences observed.
• Sweat sodium concentration decreased significantly in the control group from day 1 to day 10, but remained unchanged in the bromocriptine group.

Conclusions:

• Prolactin appears to be involved in the acclimatization-related changes observed in sweat gland function.
• Increased central dopaminergic activity, induced by bromocriptine, may attenuate sweat gland adaptation during heat exposure.
• These findings suggest prolactin plays a role in regulating sweat gland function during heat acclimatization.