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1 Nomifensine, an inhibitor of endogenous catecholamine re-uptake, did not affect the growth hormone (GH) or prolactin levels in patients with acromegaly or hyperprolactinaemia. It does not, therefore, have any therapeutic role in these conditions at the dosage used in this study. 2 It had no effect on thyrotrophin-releasing hormone (TRH)-induced thyrotrophin (TSH) or prolactin release in males, yet caused marked suppression of monoiodotyrosine (MIT)-induced prolactin release in males but not in females. 3 The significant suppression of MIT-induced prolactin release in males is likely to reflect the dopamine (DA) agonist activity of the drug and its lack of effect in the other situations tested could be dose related.4 It is proposed that the difference in male and female patterns of prolactin response to MIT after nomifensine, could be due to a 'damping' effect of oestrogen on the hypothalamic dopaminergic system.

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Background: The preliminary results of the IMPACT trial have shown that aromatase inhibitors are the preferred first‐line hormonal treatment for advanced breast cancer. This raises the question as to the significance of circulating testosterone levels in women with breast cancer. Method: We have measured serum testosterone and sex hormone‐binding globulin (SHBG) preoperatively in women presenting with primary operable breast cancer and age‐matched controls. Tumour androgen receptor (AR) expression was measured by flow cytometry on tumour biopsies from 35 patients, and serum testosterone levels were correlated with tumour expression. Results: No correlation was found between serum androgen levels and tumour androgen receptor expression. Conclusions: These results suggest that elevated circulating total testosterone has a role in the aetiology of the breast cancer, presumably by conversion to oestrogens. The finding of a significantly raised free androgen index in postmenopausal controls suggests that ‘active’ testosterone may be protective against the development of breast cancer. This is supported by cell line work, which has shown a growth‐inhibitory affect of androgens on breast cancer proliferation.