[10] Autoradiographic techniques for localizing protein hormones in target tissue

Autoradiography is an extremely useful method for determining the distribution of radioactive compounds including steroid, protein, and peptide hormones at the level of the organ, tissue, or cell. The method involves coating thin tissue sections containing radioactive hormones with photographic emulsion, exposing the emulsion for variable times, and then converting the invisible latent images into visible silver grains. The distribution of revealed radioactivity can be correlated with histological and histochemieal results obtained with adjacent serial sections. Although autoradiographic methods have improved steadily over the past several years, advances in protein hormone autoradiography have been slow. With the recent development of gentle methods for preparing biologically active, labeled protein hormones, this situation has changed and numerous autoradiographic studies concerning the localization and mechanism of action of labeled protein hormones have appeared.