Blood flow in the Dunning R3327H rat prostatic adenocarcinoma; effects of oestradiol and testosterone.

Copenhagen X Fischer F1 rats were implanted with Dunning R3327H prostatic adenocarcinoma and studied over a period of three weeks. The tumour volumes in intact and testosterone supplemented castrated rats showed parallel increases. After castration alone the tumour volumes decreased. Treatment of castrates with oestradiol and testosterone combined produced an arrest of tumour growth, suggesting that oestradiol had a direct inhibitory effect on tumour growth. Blood flow in tumours was measured using the microsphere technique. In intact rats, tumour blood flow per unit of weight decreased with increasing weight of tumours and blood flow in peripheral parts was higher than in central parts of large tumours. Oestradiol in combination with testosterone increased tumour blood flow.