Effect of testosterone on morphine withdrawal syndrome in rats.
OBJECTIVE
To determine whether testosterone is involved in morphine withdrawal syndrome (WS).


METHODS
In order to induce dependency, rats were treated with subcutaneous injection of morphine (days 1-2, 5 mg/kg; days 3-5, 7.5 mg/kg; days 6-8, 10 mg/kg), and after the last dose of morphine (day 8) WS was induced by intraperitoneal injection of naloxone (1 mg/kg). Wet dog shake (WDS), abdomen writhing (AW), and jumps (J) were recorded as indicators of WS.


RESULTS
The severity of WDS, AW, and J in male rats was greater than that in females. Accordingly, in 4-week castrated and flutamide-treated (10 mg/kg/day for 8 days, i.p.) male rats, WDS, AW, and J were significantly decreased compared to male control rats. Testosterone replacement therapy (10 mg/kg/day for 8 days, i.m.) in 4-week castrated rats restored the severity of WDS, AW, and J behaviors to the level of non-castrated male rats, whereas testosterone potentiated the WDS behavior in non-castrated male rats.


CONCLUSIONS
It can be concluded that testosterone might be effectively involved in morphine WS.
Nayebi
Ali Reza Mohajjel
AR
Department of Pharmacology and Toxicology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz 51664, Iran. nayebia@yahoo.com
Rezazadeh
Hassan
H
D000726:Androgen Antagonists / Q000494:pharmacology; D000728:Androgens / Q000494:pharmacology / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal; D005260:Female; D005485:Flutamide / Q000494:pharmacology; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009021:Morphine Dependence / Q000503:physiopathology*; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009294:Narcotics / Q000494:pharmacology*; D009919:Orchiectomy; D051381:Rats; D017208:Rats, Wistar; D012720:Severity of Illness Index; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology*; D013739:Testosterone / Q000494:pharmacology / Q000502:physiology*
D000726:Androgen Antagonists; D000728:Androgens; D009292:Narcotic Antagonists; D009294:Narcotics; D009270:Naloxone; D013739:Testosterone; D009020:Morphine; D005485:Flutamide