ZONAL BIOCHEMICAL AND MORPHOLOGICAL-CHARACTERISTICS IN BPH

Objective To compare androgen, oestrogen, progesterone and epidermal g rowth factor receptor concentrations in the transition zone and periph eral zone of the prostate in benign prostatic hyperplasia (BPH), and t o relate these findings to epithelial and stromal composition. Patient s and methods Tissue from both the transition and peripheral zone of t he prostate was obtained from 26 patients undergoing transurethral pro statectomy for benign prostatic obstruction and used for both receptor binding studies and morphometric analysis, Androgen receptor (AR), oe strogen receptor (ER), progesterone receptor (PR) and epidermal growth factor receptor (EGFR) concentrations were assayed by saturation bind ing with a competitive inhibitor, The epithelial. stromal and luminal composition of the tissue was determined using a Zeiss AxioHOME micros cope workstation. Results The epithelial content was significantly gre ater in the transition zone than in the peripheral zone. No overall zo nal difference in AR concentration was detected; however, when values were expressed relative to the epithelial component, the AR content wa s significantly higher in the peripheral zone, Conversely, overall EGF R concentrations were significantly greater in the transition zone, al though not when expressed per unit epithelium. Higher concentrations o f oestrogen receptor were measured in the transition zone per unit str oma, No zonal difference in PR was detected, However, there was a sign ificant correlation between AR and PR in the peripheral zone and betwe en EGFR and AR in the transition zone. Conclusion These data demonstra te that receptor concentrations should be related to tissue compositio n. Concentrations of AR were higher in the peripheral zone epithelium than in transition zone epithelium, suggesting greater androgen depend ence, This may be important in determining its greater propensity for malignancy, Although EGFR concentrations were greater in the transitio n zone, there was no zonal difference after correction for the amount of epithelium, Finally, higher concentrations of ER were detected in t he transition zone stroma which may reflect important zonal difference s in regulating growth and provides further evidence of a role for oes trogens in BPH.