Analysis of cholinesterases in human prostate and sperm: Implications in cancer and fertility

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are postulated to play non-cholinergic roles in cellular physiology. The probable implication of cholinesterases (ChEs) in several human pathologies prompted us to study the cholinergic components in the male reproductive system. Surgical pieces of prostatic cancer (PC) and benign prostatic hyperplasia (BPH) were analyzed for AChE and BChE activity. Loosely (S1) and tightly (S2) bound AChE and BChE forms were characterized by sedimentation analysis. The mean AChE activity in BHP samples was 2.38 ± 0.56 mU/mg (nmol of the substrate hydrolysed per minute and per milligram protein) and 2.57 ± 0.61 mU/mg in S1 and S2, respectively. The AChE activity did not vary with cancer, showing 2.46 ± 0.45 mU/mg in S1 and 2.70 ± 0.53 mU/mg in S2 from PC samples. Amphiphilic dimers and monomers and hydrophilic dimers of AChE were identified in BHP and PC tissues. Their contribution was affected by cancer with a great increase in hydrophilic dimers in the cancerous samples. Significant levels of both AChE and BChE activities were found in seminal fluid and homogenates from spermatozoids. Enzymatic activity dropped in samples with abnormal seminal parameters as sperm count and mobility.