SHBG on Testosterone Recovery

lutions give parallel curves for T for both pooled sera. Counts of the tritiated T were identical in both cases (data not shown). Our data, which are in agreement with Masters and Hfihnel (1) and also with Slaats et al. (3), clearly verify that SHBG strongly influences the equilibrium adjustment of the binding reaction between ligand and antibody-the most important step in immunometric measurements. Use of the extraction technique totally abolishes the influence of SHBG. The question the clinical chemist must ask in this context is the following: what is the clinical relevance of precise determination of T in serum, especially in the lower range? Doubtless, it is the diagnosis of hyperandrogenism in hirsute women. But it must be considered that, in these patients, concentrations of SHBG in serum are usually diminished. Therefore the SHBG effect is of minor importance in the measurement of T. Nevertheless, this problem can be overcome by doveloping adequate SHBG-dissociating agents for no-extraction assays, because practical reasons argue against the use of extraction assays for T.