134 ASSESSMENT OF ADRENAL AUTOTRANSPLANTATION IN THE RAT BY WEIGHT GAIN AND STRESS RESPONSE

Abstract

Because results of human adrenal autotransplants have been variable, we evaluated adrenal autotransplantation in rats. Female Sprague-Dawley rats were assigned to three groups: (1) bilateral adrenalectomy (ADx,n=8), (2) bilateral adrenalectomy with immediate autotransplantation of one-third of a gland to a flank muscle pocket (Tx,n=6) and (3) sham operation (S,n=6). The adrenal capsule was included with the transplant. Rats were randomly housed in pairs, provided saline and all survived the study. Adrenal function was assessed at 2, 4 and 6 weeks following surgery by measurement of corticosterone (C) 15 min after ether exposure to unconsciousness. Data from one animal in the Tx group was excluded because of finding residual adrenal tissue present in the retroperitoneum at autopsy. Weights of ADx animals were significantly below the other groups throughout the study (p < .01). The mean S group weight was not different from the Tx group after 2 weeks. Greater C concentrations were found in the S group at all study points. Mean C concentrations were not significantly different between ADx and Tx groups until 6 weeks. These observations indicate that in rats, one-third of an adrenal gland can be successfully autotransplanted to a muscle pocket. Graft function can be demonstrated at 2 weeks by comparison of body weight to ADx animals and at 6 weeks by comparison of C concentrations. This model can be used for studies with cryopreserved tissue along with radionuclide and NMR assessment of graft function.