Electrophysiological studies on isolated human eccrine sweat glands

Area of Science:

• Physiology
• Cell Biology
• Membrane Electrophysiology

Background:

• Human eccrine sweat glands are crucial for thermoregulation.
• Understanding their cellular electrophysiology is key to comprehending sweat secretion mechanisms.
• Previous studies have not fully elucidated the electrical properties of the basolateral membrane and responses to neurotransmitters.

Purpose of the Study:

• To investigate the electrical properties of the basolateral membrane of human eccrine sweat glands.
• To determine the effects of acetylcholine on sweat gland membrane potential and input impedance.
• To explore the modulatory roles of atropine and ouabain on acetylcholine-induced responses.

Main Methods:

• Isolation of human eccrine sweat glands by shearing.
• Measurement of basolateral membrane potential differences using bevelled micro-electrodes.
• Determination of input impedance via constant current injection.
• Application of acetylcholine, atropine, and ouabain to assess their effects on membrane potential and impedance.

Main Results:

• Stable resting potentials of up to -81 mV were recorded, indicating significant basolateral membrane polarization.
• Altering external potassium concentration demonstrated high potassium permeability of the basolateral membrane.
• Acetylcholine induced varied responses, including depolarization and hyperpolarization, with distinct input impedance changes.
• Atropine reversibly inhibited acetylcholine effects, while ouabain irreversibly reduced them.

Conclusions:

• The basolateral membrane of human eccrine sweat glands is largely permeable to potassium.
• Acetylcholine elicits complex electrical responses in sweat gland cells, suggesting diverse signaling pathways.
• These findings provide critical insights into the electrophysiological mechanisms governing eccrine sweat gland function and neurotransmitter modulation.