Renin-like (angiotensinogenase) activity in human eccrine sweat

Area of Science:

• Biochemistry
• Physiology
• Dermatology

Background:

• Renin-angiotensin system (RAS) plays a crucial role in blood pressure regulation.
• Extrarenal renin production is implicated in various physiological processes.
• Human eccrine sweat glands are a potential site for extrarenal renin synthesis.

Purpose of the Study:

• To investigate the presence and characteristics of renin-like activity (RLA) in human eccrine sweat.
• To explore the regulation of RLA in sweat glands, particularly the role of adrenergic receptors.
• To assess the potential of human sweat glands as a model for studying extrarenal renin release.

Main Methods:

• Incubation of human sweat with purified sheep angiotensinogen.
• Measurement of RLA using rat bioassay and angiotensin I radioimmunoassay.
• Stimulation of sweat glands via cholinergic agents, isoprenaline, and dibutyryl-c-AMP.
• Pharmacological blockade of beta-adrenergic receptors with propranolol.

Main Results:

• Renin-like activity (RLA) was detected in human eccrine sweat, with levels significantly higher than plasma.
• Cholinergic stimulation resulted in measurable RLA, while beta-adrenergic activation (isoprenaline) did not exceed cholinergic levels.
• Beta-adrenergic blockade (propranolol) led to unmeasurably low RLA.
• Local injection of dibutyryl-c-AMP increased RLA values.

Conclusions:

• Human sweat glands possess renin-like activity, suggesting potential local renin synthesis.
• RLA release in sweat glands is regulated by beta-adrenergic pathways.
• Human eccrine sweat glands offer a viable model for investigating extrarenal renin release mechanisms.