Experimental study on adrenal autografts in rats to preserve normal adrenocortical function after bilateral adrenalectomy

Effects on plasma corticosterone levels and brain serotonin from interference with methamphetamine-induced corticosterone release in neonatal rats

Methamphetamine (MA) induces multiple effects in rats including alterations to corticosterone (CORT) and adrenocorticotropic hormone (ACTH). This effect is age dependent showing a U-shaped function similar to that of other stressors during the stress hyporesponsive period. Neonatal MA treatment leads to adult learning and memory impairments, but whether these are related to MA-induced CORT release is unknown. Here in, four methods were tested in neonatal rats previously established in adult rats for inhibiting stress-induced CORT release: inhibiting synthesis (metyrapone (MET) or ketoconazole (KTZ)) or surgically by adrenalectomy or adrenal autotransplantation (ADXA). Pretreatment on postnatal day 11 with MET or KTZ prior to four doses of 10 mg/kg of MA initially suppressed MA-induced increases in plasma CORT, but 24 h later, even with additional inhibitor treatment, a large CORT increase was seen which exceeded that of MA alone. Adrenalectomy blocked MA-induced increases in CORT but caused a secondary effect on brain serotonin (5-HT) and dopamine (DA), causing greater reductions than those caused by MA alone. ADXA inhibited MA-induced CORT release without causing a 24-h CORT increase and did not produce additional effects on brain 5-HT or DA. Neonatal ADXA is a new model for developmental drug or stress experiments designed to test the role of CORT in mediating early effects on later outcomes.

Effects of inhibiting neonatal methamphetamine-induced corticosterone release in rats by adrenal autotransplantation on later learning, memory, and plasma corticosterone levels

RATIONALE

Neonatal rat methamphetamine (MA) exposure has been shown to cause long-term behavioral impairments similar to some of those observed following neonatal stress. The mechanism by which MA induces impairments is unknown but may be related to early increases in corticosterone release. We previously developed a method to attenuate MA-induced corticosterone release using adrenal autotransplantation (ADXA) in neonatal rats. This exposure period corresponds to the second-half of human pregnancy.

OBJECTIVE

To determine whether inhibition of neonatal MA-induced increases in corticosterone attenuates the long-term behavioral deficits associated with early MA treatment.

RESULTS

ADXA successfully attenuated MA-induced plasma corticosterone increases by approximately 50% during treatment (P11-20) but did not attenuate the long-term behavioral effects of MA treatment. MA-treated rats, regardless of surgery, showed increased errors and latencies in the Cincinnati water maze test of egocentric learning and increased latency, path length, and cumulative distance in three phases of Morris water maze spatial learning and reference memory. MA-treated offspring were hypoactive, had subtle reductions in anxiety in the elevated zero maze but not in the light-dark test. ADXA had no effect on MA-induced long-term 5-HT reductions in the neostriatum or entorhinal cortex or on 5-HIAA reductions in the hippocampus.

CONCLUSIONS

Fifty percent attenuation of neonatal MA-induced elevations in corticosterone does not alter the long-term egocentric or allocentric learning deficits or other behavioral effects of neonatal MA exposure. Because the ADXA effect was partial, the data cannot rule out the possibility that a more complete block of MA-induced corticosterone release might not prevent later cognitive deficits.

Neonatal methamphetamine-induced corticosterone release in rats is inhibited by adrenal autotransplantation without altering the effect of the drug on hippocampal serotonin

Rat neonatal methamphetamine exposure results in corticosterone release and learning and memory impairments in later life; effects also observed after neonatal stress. Previous attempts to test the role of corticosterone release after methamphetamine using corticosterone inhibitors were unsuccessful and adrenalectomy caused reductions in hippocampal serotonin greater than those caused by methamphetamine alone. Here we tested whether adrenal autotransplantation could be used to attenuate methamphetamine-induced corticosterone release without also altering the effects of the drug on serotonin. Adrenal autotransplantation surgery occurred on postnatal day 9 followed by methamphetamine or saline treatment from postnatal day 11-20 (10mg/kg/dosex4/day). Plasma corticosterone and hippocampal serotonin and 5-hydroxyindoleacetic acid were determined 30min following the first treatment on each day between postnatal days 11-20. Adrenal autotransplantation attenuated neonatal methamphetamine-induced corticosterone release by approximately 70% initially, approximately 55% midway through treatment, and approximately 25% by the end of treatment. Methamphetamine reduced serotonin and 5-hydroxyindoleacetic acid in the hippocampus in the ADXA rats to the same degree as in SHAM rats. The data show that neonatal adrenal autotransplantation is an effective method for partially reducing treatment-induced corticosterone release while providing sufficient corticosterone to sustain normal growth and development. The method should be applicable to other models of developmental stress/corticosterone release.

Successful autotransplantation of an adrenal gland using a new method of omental wrapping: report of a case

Bilateral total adrenalectomy results in the need for patients to take lifelong supplements of adrenal steroids, with the risk of possible Addisonian crisis. Few reports of the successful autotransplantation of adrenal tissue in muscular pockets have been documented; however, we describe herein the case of a 22-year-old woman in whom autotransplantation of an adrenal gland was successfully performed employing a new method of omental wrapping. The patient underwent bilateral total adrenalectomy for bilateral pheochromocytoma at which time adrenal tissue was sliced into 1-2-mm thick pieces, half of which were placed in muscular pockets in the abdominal rectus muscles, and the remaining half put onto the omentum and wrapped with it. Laboratory examinations done 6 months after surgery showed recovery of her adrenal function, and 4 months later steroid supplements were able to be discontinued. Scintigraphic studies using [131I]-iodomethyl-norcholesterol ([131]I-Adosterol) demonstrated clear activity in the omentum, weak activity in the rectus muscles, and no activity in the adrenal beds. These findings suggest that the omentum may be more suitable as an implantation site for adrenal tissue than muscular pockets.