Adrenal cortex transplantation after bilateral total adrenalectomy in the rat

An experimental animal model with adrenal cortex transplantation was developed to study adrenal cortex replacement therapy in patients with multiple endocrine neoplasia type 2 who have had bilateral adrenalectomy for pheochromocytomas. Adrenal cortex of syngenetic rats was isolated from the medulla by collagenase digestion and a defined sedimentation. The cell suspension of the cortical cells was implanted under the kidney capsule of untreated syngenetic rats. After two weeks the recipients were bilaterally adrenalectomized. Serum corticosterone levels were measured as an estimate of function of the grafts. All recipients were healthy throughout the observation period, whereas all adrenalectomized controls died within 18 days. Vital cortex cells could be demonstrated in the explanted grafts by immunohistochemistry. Corticosterone levels of transplanted animals were nearly normal (9.5 ng/100 mL +/- 0.4) compared to the controls (0.20 ng/mL +/- 0.06). This animal model of adrenal cortex transplantation allows the separation of medullary from cortical cells. After transplantation, these cortical cells survived for eight weeks and were able to replace the adrenal cortex function.