Functional and morphological changes in the eccrine sweat gland with heat acclimation.

Area of Science:

• Physiology
• Thermoregulation
• Primate Research

Background:

• Heat acclimation is crucial for survival in hot environments.
• Understanding sweat gland function is key to thermoregulation.
• Patas monkeys serve as a model for studying heat adaptation.

Purpose of the Study:

• To investigate the effects of prolonged heat acclimation on sweat gland morphology and function in patas monkeys.
• To determine if heat acclimation enhances sweat production and efficiency.

Main Methods:

• Patas monkeys underwent prolonged heat exposure (33°C for 9 months, with intermittent 45°C exposure).
• Heat tolerance tests measured rectal temperature, skin temperature, heart rate, and sweat rate (msw) before and after acclimation.
• In vivo and in vitro sweat gland responses to methacholine (MCh) stimulation were assessed.
• Sweat gland morphology (tubular length and volume) was analyzed.

Main Results:

• Heat acclimation reduced rectal and skin temperatures during heat exposure.
• Maximal sweat rate (msw) increased significantly, both in vivo and in vitro.
• Sweat gland size (tubular length and volume) increased post-acclimation.
• Sweat production per unit length of secretory coil also showed a significant increase.

Conclusions:

• Heat acclimation in patas monkeys leads to hypertrophy of eccrine sweat glands.
• These enlarged sweat glands exhibit increased sweat output and enhanced efficiency.
• The findings provide insights into the physiological adaptations underlying heat tolerance.