NEUROSTEROIDS AND THE NALOXONE-PRECIPITATED WITHDRAWAL SYNDROME IN MORPHINE-DEPENDENT MICE

The effects of some neurosteroids on behavioral and hormonal markers o f the naloxone-precipitated withdrawal syndrome in morphine-dependent mice were examined. 5 alpha-Pregnane-3,20-dione inhibited dose-depende ntly the jumping behavior and the number of forepaw tremors, at a dose of 5 mg/kg it attenuated body weight loss; deoxycorticosterone acetat e inhibited dose-dependently the jumping behavior and body weight loss , whereas dehydroepiandrosterone in a dose of 1 mg/kg prevented body w eight loss, and in a dose of 20 mg/kg forepaw tremor. The other steroi ds tested had no significant effect on the morphine withdrawal syndrom e. None of the neurosteroids influenced the increased plasma corticost erone level in the naloxone-precipitated morphine withdrawal syndrome. The above results indicate that 5 alpha-pregnane-3,20-dione, deoxycor ticosterone acetate and dehydroepiandrosterone, but not other neuroste roids tested, alleviate some signs of the morphine abstinence syndrome in mice.