Growth hormone and prostatic tumours: localization using a monoclonal human growth hormone antibody

The immunocytochemical detection of endogenous human GH and the binding of exogenously applied human GH in tumour tissue from patients with benign prostatic hyperplasia or prostatic carcinoma is reported. Monoclonal human GH antibody binding was exclusively to the connective tissue in both benign and carcinomatous specimens. Specificity control experiments indicated that the antibody could be absorbed with human GH but not with human prolactin. Preincubating the sections with human GH considerably altered the immunocytochemical staining, reducing the reaction product within the connective tissue in a concentration-dependent manner and revealing a binding site for GH within the cytoplasm of epithelial cells.