Adenosine deaminase specific activity in normal, benign hypertrophied and neoplastic human prostate tissue

The finding that deficiency in the purine salvage pathway enzyme, adenosine deaminase (ADA), is associated with immunodeficiency suggests that this enzyme may be crucial for normal function of immunocompetent cells in man. We have therefore examined ADA activity in human prostatic tissue. Mean values were as follows: normal tissue, 0.37 mumol substrate turned over/h/mg protein; carcinoma, 0.33; benign prostatic hypertrophy (BPH), 1.22. ADA activity in normal and carcinoma prostate tissue differed significantly from BPH (p = 0.001), but were individually indistinguishable. Thus, there may be a cellular level of immunostimulation in BPH relative to normal prostatic tissue which is no longer detectable in overt carcinoma.