Assessment of Nitric Oxide Synthase Protein Level in the Scalp of Androgenetic Alopecia

Abstract Background Androgenetic alopecia (AGA) is the most common form of hair loss in males due to excessive response to androgens causing thinning of hair. Nitric oxide synthase is an enzyme catalyzing production of nitric oxide. Dihydrotestosterone induced nitric oxide synthase expression and NO production in dermal .papilla cells of the hair follicle Objective Investigation of the level of nitric oxide synthase protein expression in the scalp of men with androgenetic alopecia .and the possible link to the pathogenesis of androgenetic alopecia Patients and Methods A total of 40 patients were enrolled and divided into two equal groups; study group included 20 patients with androgenetic alopecia and control group included 20 healthy controls. A biopsy was taken from the androgenetic site and another from the non-androgenetic site in both patients and controls. A 3 mm punch is used to remove a small core of skin including epidermis and dermis. Tissue nitric oxide synthase. protein expression was compared between study groups Results Our study revealed that tissue nitric oxide synthase protein expression was statistically higher in androgenetic site in patients compared to non-androgenetic sites in patients 17.18±5 vs. 3.06±1.6 and higher in androgenetic sites of patients compared to androgenetic sites in controls. 17.18±5 vs. 3.32±0.8 respectively. Nitric oxide synthase at cut-off point 4.39 showed excellent discriminative power with 100% sensitivity and Also, Patients with Hypertension and on antihypertensive therapy had higher levels of nitric oxide synthase levels in androgenetic site compared to androgenetic sites of patients with AGA with or without systemic diseases other than hypertension. In our study, no significant correlations were detected between nitric oxide synthase and either of age or duration of disease in both androgenetic and non-androgenetic sites of patients with test values -0.236, 0.136, -0.157 and -0.119 respectively. On the other hand, no differences were noted between study groups regarding smoking and past history of surgical operations. Also, no significant difference between Nitric oxide synthase levels and grades of Hamilton scale in either. androgenetic or non-androgenetic sites of patients Conclusion Nitric oxide acts as a signaling molecule in human dermal papilla cells and implicate basal and androgen-mediated NO production to be involved in the regulation of hair follicle .activity