Estrogen receptors in rabbit thymus

The estrogen receptors presence or absence in the thymus gland represents the basic element to assert or to exclude any estrogenic action in the thymus. Now we have measured the presence of cytoplasmatic estrogen receptors in the female rabbits thymus, using some methods (sucrose gradient, protamine sulphate, dextran-coated charcoal). Finally, we have investigated, using the sucrose gradient assay, the nuclear ER presence in 1000g thymic pellet. The results exclude high levels of estrogen-binding proteins while don't suggest their total absence in the female rabbit thymus.