Skin research and drug localization with receptor microscopic autoradiography.

For the localization of drugs and related functional characterization, cellular-subcellular resolution can be achieved with radiolabelled compounds of high specific activity and receptor microscopic autoradiography, which is the method of choice for high-resolution qualitative and quantitative imaging. Detailed information together with integrative surveys can be obtained which is impossible with other methods. The history of discoveries of drug targets testifies to the utility and potential of receptor microscopic autoradiography that was designed to preserve in vivo conditions by excluding any liquid treatment during tissue preparation and to avoid translocation and loss of diffusible compounds. Examples of autoradiograms include in vivo applications of 3H-vitamin D, 3H-OCT (oxacalcitriol), 3H-oestradiol and 3H-retinoic acid. For topical applications, routes of delivery and sites of deposition and retention are demonstrated.