Anabolic androgenic steroids affects alcohol intake, defensive behaviors and brain opioid peptides in the rat

The present study investigated whether a relationship exists between nandro lone decanoate and voluntary ethanol intake in laboratory rats. Animals wer e subjected to daily subcutaneous injections with nandrolone decanoate (15 mg/kg) during 2 weeks. One group of animals was tested for voluntary alcoho l intake 1 week after the end of the 2-week treatment period and another gr oup received alcohol 3 weeks after the treatment. In addition, assessment o f defensive behaviors and immunoreactivity (ir) levels of the brain opioid peptides dynorphin B and Metenkephalin-Arg-Phe (MEAP) were performed. The n androlone decanoate-treated animals were significantly more aggressive and showed lower fleeing and freeezing reaction than the oil-treated controls. Treatment with nandrolone decanoate enhanced voluntary alcohol intake, rega rdless if it was presented 1 or 3 weeks after end of the treatment period. These animals had a decreased activity of dynorphin B-ir in the nucleus acc umbens, decreased levels of MEAP-ir in the periaqueductal gray (PAG) and hi gher levels of MEAP-ir in the hypothalamus compared to controls. In line wi th previous studies, this suggests that the altered dynorphin B-ir activity may promote the rewarding effects of ethanol and thereby increasing alcoho l intake, whereas MEAP-ir may be associated with the ability to control the aggressive reaction. Abuse of nandrolone decanoate may thus constitute a r isk factor for increased alcohol consumption and defensive aggression. In h uman, this constellation of behavioral symptoms is closely related to acts of crimes and violence and is often observed among those abusing anabolic a ndrogenic steroids. (C) 2000 Elsevier Science Inc. All rights reserved.