Transplantation of fetal adrenal glands in syngeneic rat strains

In a syngeneic rat model we investigated the feasibility of fetal adrenal gland transplantation into adult recipient animals. We determined the optimal site of graft implantation by morphological criteria. Transplantation into the omentum majus proved superior to transplantation underneath the fascia of the rectus abdominis muscle possibly due to superior access to vascular supply. We assessed transplant function by sequential determinations of serum corticosterone, aldosterone, sodium and body weight. We compared rats which received syngeneic fetal adrenal transplants and underwent excision of their own adrenal glands four weeks thereafter to control animals without adrenalectomy or transplantation and to adrenalectomized animals without prior transplantation. The total study period was 16 weeks. Whereas all adrenalectomized rats without prior transplantation died within 2 weeks, all the animals which had received fetal adrenal grafts survived. Their serum sodium remained within normal limits. Weight gain and serum corticosterone levels were decreased when compared to control animals. Aldosterone levels dropped intermittently but had normalized by 16 weeks. We conclude that fetal adrenal grafts may be able to substitute for the animals' own adrenal glands in the syngeneic model.