| Abstract: | The effect on serum PRL levels of lowering serum oestradiol (E2) concentration by short-term administration of an aromatase activity inhibitor, hydrotestolactone (HT), was studied in six healthy male subjects. After HT administration serum E2 levels decreased from 68 ± 5±8 to 26 ± 2±5 pmol/1 (mean ± SE, P < 0±05). These E2 changes were accompanied by a significant decrease in mean 2-h PRL levels from 11±2 ± 2±1 to 6±5 ± 1±6 ng/ml mean ± SE, P < 0±05). The evaluation of individual percentage change from basal concentrations showed a varying decrease in all subjects. These findings suggest that under physiological conditions E2 may be one of the factors which control blood PRL concentrations in men. |
