[Tissue specificity of testosterone fixation: demonstrated by ultrastructural immunocytochemistry after cryoultramicrotomy].

Testosterone can be detected by immunocytochemistry on ultrathin slices obtained by cryoultramicrotomy. Testosterone detected by this method is likely bound on a binding site having a high affinity. In order to study the tissue specificity of this binding, testosterone was tested in Rat pituitary gland, liver and adrenal glands. Immunoreactive testosterone was detected in the gonadotropic cells of the pituitary gland, in the hepatocytes. Testosterone was not detected by immunocytochemistry in the pituitary cells other than the gonadotropic cells and in the cells of the medulla of adrenal glands. These data testify in favour of tissue specificity of the testosterone binding.