Relationship Between Amyloid Precursor Protein in Seminal Plasma and Abnormal Penile Sympathetic Skin Response in Lifelong Premature Ejaculation.

ABSTRACT

INTRODUCTION: Hyperactivity of the sympathetic nervous system can play an important role in lifelong premature ejaculation (PE). Our previous study found that amyloid precursor protein (APP) levels in seminal plasma of patients with PE were clearly increased. Amyloid-ß (Aß) is derived from APP. Excessive Aß, especially Aß42, can cause neuronal dysfunction. AIM: To determine whether APP and Aß42 are associated with an abnormal penile sympathetic skin response (PSSR). METHODS: From November 2015 to April 2016, 24 patients with lifelong PE (mean age = 29.2 ± 5.3) with self-estimated intravaginal ejaculatory latency time no longer than 2 minutes and 10 control subjects (mean age = 28.0 ± 5.5) were enrolled consecutively from andrology clinics. PSSR was measured in patients with lifelong PE. APP and Aß42 levels in seminal plasma were determined. MAIN OUTCOME MEASURES: PSSR in patients with lifelong PE and APP and Aß42 levels in all subjects. RESULTS: Patients with PE presented 1.5-fold higher levels of APP (P = .004) than control subjects. Seminal plasma protein concentration (C) in the PE group was lower than that in the control group (P = .007). APP divided by C (APP/C) was 2.0-fold higher (P < .001) in the PE group. Aß42 level was not different between the PE and control groups, but Aß42 divided by C (Aß42/C) was significantly higher in the PE group (P < .001). No differences in APP and APP/C were found between patients with PE in the abnormal and normal PSSR groups. The abnormal PSSR group presented significantly higher Aß42 (P = .007) and Aß42/C (P < .001) levels. The latency of PSSR was negatively correlated with Aß42/C (r = -0.436; P = .033). CONCLUSION: These results showed that patients with lifelong PE had higher APP and Aß42 levels in seminal plasma. Abnormal PSSR was related to a higher Aß42 level. Drugs that decrease Aß could be treatment of PE.