The utility of antiserums to subunits of TSH and LH for immunochemical staining of the rat hypophysis

The objective was to assess the effectiveness of antiserums to the β‐subunit of bovine TSH (thyrotropin) and α‐ and β‐subunits of LH (luteinizing hormone) for immunochemical staining of rat pituitary cells and in so doing to acquire more information about the properties of the subunits. For the following reasons it was concluded that antiserum to TSH‐β is specific for demonstration of TSH‐cells. The morphology and distribution of the presumptive TSH‐cells so revealed conform to the descriptions presented by other investigators who have used histological techniques. When pituitary TSH content was reduced by thyroidectomy or administration of propylthiouracil or thyroxine, the stainability of TSH‐cells was reduced; it was increased with elevation of TSH content during rebound after cessation of propylthiouracil treatment. The effectiveness of anti‐TSH‐β was lost after absorption with bovine TSH. The specificity of antiserum of LH‐β for demonstration of LH‐cells was indicated since the cells demonstrated with it correspond to the gonadotropic cells described by others with respect to morphology, distribution and response to gonadectomy. Antiserum to LH‐α, the nonspecific subunit of LH, permitted staining of both TSH‐ and LH‐cells. The individuality of TSH‐ and LH‐cells, as revealed immunochemically with antiserums to the respective specific β‐subunits, was demonstrated by double staining and by comparison of adjacent sections stained with one of the two antiserums.