The prostate gland attracts attention and achieves notoriety because of the disorders of growth which beset it during the later stages of life of the human male. Improving longevity increases the incidence of these age-related diseases (Carter & Coffey, 1990). More than 50% of men in the U.K. and U.S.A. have some degree of benign prostatic hyperplasia (BPH), presaging a major impact in terms of morbidity, mortality and health-care costs (Carter, Carter & Isaacs, 1990a; Carter & Coffey, 1990; Griffiths, Davies, Eaton et al. 1991). Even more alarmingly, carcinoma of the prostate is the fourth most common cause of death from malignant disease in the U.K., being responsible for approximately 4000 deaths each year (Griffiths et al. 1991). In the U.S.A., approximately 100 000 new cases present each year, with 28 000 deaths (Carter et al. 1990a; Carter & Coffey, 1990). The prostate gland is the frequently chosen model