Increase in bombesin-like peptides in the spinal cord after dexamethasone treatment of adrenalectomized rats

The potential influence of corticosteroids on the bombesin (BN)-like peptid e family is unknown. Therefore, the effects of adrenalectomy (ADX) on the n ervous system of Sprague-Dawley rats, some of them being treated with high doses of the synthetic glucocorticoid dexamethasone (DEX), were investigate d. After 8-10 days of treatment, the rats were sacrificed and tissues were prepared for radioimmunoassay (RIA) and immunohistochemical examination. We found an increase in BN-like immunoreactivity in the superficial layers of the dorsal horn of the lumbar spinal cord in the ADX + DEX animals. This i ncrease was confirmed by RIA (P < 0.05). The observations show that the exp ression of BN-like peptides is influenced by glucocorticoids. The altered l evels of BN-like peptides may be related to the trophic and antinociceptive effects previously reported for these peptides. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.