Autoradiographic localization of 3H-diprenorphine in the Syrian hamster

An autoradiographic technique is reported for the in vivo localization in the Syrian hamster of small doses of the opiate antagonist, 3H-diprenorphine. The regional distribution in the hamster brain was similar to that reported in the rat. The adrenal medulla showed a high degree of localization providing supportive evidence for the presence of opiate receptors in the medulla and a possible paracrine function for opioid peptides in this site. Other peripheral sites showed selective uptake of 3H-diprenorphine which was not apparently related to the vascularity of the tissue.