Overexpression of AQP5 Was Detected in Axillary Sweat Glands of Primary Focal Hyperhidrosis Patients.

BACKGROUND: The expression of aquaporin 5 (AQP5) in human axillary sweat glands has never been studied so far. OBJECTIVE: To detect the expression of AQP5 in axillary sweat glands of patients with primary focal hyperhidrosis (PFH) relative to control subjects. METHODS: The morphological characteristics and the number of sweat coils in axillary sweat glands were compared between two groups by using transmission electron microscopy. The expression of AQP5 was detected by immunohistochemistry, Western blot analysis, and real-time transcription polymerase chain reaction. RESULTS: There were no significant differences between the two groups in terms of morphological characteristics and the number of sweat coils in axillary sweat glands. The expressions of AQP5 protein and AQP5 mRNA were significantly higher in the patient group than in the control group. CONCLUSION: AQP5 is involved in the secretion of human axillary sweat glands. The overexpression of AQP5 in sweat glands is probably one pathogenetic mechanism underlying PFH.