[Quantitative determination of proteins in the cytosol fractions of human and rat sex steroids after precipitation with protamine sulfate].

A simple procedure is developed for estimation of proteins after precipitation with protamine sulfate in cytosol fraction of human tissues-target dor sex steroids (prostate adenoma, cancer of prostate, mammalian gland cancer) and in similar target tissues of rats (ventral prostate and uterus). Human blood serum did not interfere with the protein estimation after the protamine sulfate precipitation. This method for estimation of protein using protamine sulfate might be critically important in calculation of the binding capacity of target-tissues with sex steroids (quantitative estimation of receptors), especially in human tissues because the interference of blood proteins is eliminated. The efficiency of the procedure developed was confirmed by comparative study of binding capacity of the tissues of prostate adenoma, cancer of prostate and mammalian gland cancer towards 3H-17 beta-estradiol and 3H-dihydrotestosterone, calculated per total protein and the protein precipitated by protamine sulfate.