Release of receptor-bound estradiol by heparin or dextran sulfate in combination with tetracaine.

The rapid release of 3H-estradiol from estrogen-receptor complexes at 0 degrees C is implemented by combinations of the local anesthetic tetracaine and certain sulfated polysaccharides. The simultaneous presence of both classes of compounds was found necessary for the displacement of 3H-estradiol to occur. A limited survey of some sulfated polysaccharides and other anionic compounds for their ability to synergize with tetracaine revealed a specificity for the charge-carrying polysaccharide. The present data support the view that the cooperative interaction of sulfated polysaccharides and certain charged hydrophobic compounds with estrogen receptors determines the ability of the receptors to bind estradiol.