Localization of progestin receptors in the islets of Langerhans.

Autoradiographic studies using the synthetic progestin [3H]ORG-2058 (16 alpha-ethyl-21-hydroxy-19-nor-[6,7-3H]pregn-4-ene-3,20-dione) were conducted on female baboons. Numerous silver grains from the exposed photographic emulsion appeared discretely localized over the nuclei of the islets of Langerhans of the pancreases of baboons injected with [3H]ORG-2058. These observations indicate that islet cells might contain receptors for progestins and, combined with clinical observations by others, suggest that progestins have a direct effect on the islet cells and may modulate the release of insulin and/or other islet hormones.