Tritium-labelled steroids, their preparation and application for the determination and location of steroid tissular hormone receptors

The products are prepared by action of a magnesian tritiated methyl halide on 3,3(1,2 ethanediyl bis (oxy)-estra 4,9, 11-trien-17-one to give, after acid hydrolysis, (17β)-17-hydroxy-17-methyl-3H3-estra-4,9, 11-trien-3-one; the free hydroxyl function of this product may be etherified or esterified as the case may be. The magnesian tritiated methyl halide used is the iodide and the reaction takes place in anhydrous ether at room temperature; the acid hydrolysis agent is hydrochloric acid. The free hydroxyl function is etherified by an agent such as an alcoyl or aryl halide or a dialcoyl sulphate; this function is esterified by means of a functional acid derivative such as chloride or anhydride. These products, especially (17β)-17-hydroxy-17-methyl-3H3-estra-4,9, 11-trien-3-one, show a strong affinity for androgen receptors and great metabolic stability, allowing the location, determination and study of these receptors in the cells of androgen target tissues, such as the prostate, sebaceous gland and androgen-dependent tumours, in both animals and man. Since moreover they are not fixed by plasma proteins binding the androgen proteins present in certain animal species and in man these products are especially useful for the study of androgen receptors in human tissues, avoiding interference due to contamination of the tissue preparations by plasma proteins