The Effect of Clonidine Administration into Lateral Paragigantocellularis on Morphine Withdrawal in Morphine Dependent Male Rats

Paragigantocellularis plays a role in different physiologic actions. In this study the effect of clonidine administration into lateral paragigantocellularis on morphine withdrawal syndrome in male rat was investigated. Rats were addicted to morphine by injecting 25, 30, 35, and 40 mg/kg ip twice a day for four days. In the fifth day rats received 40 mg/kg morphine and after half an hour naloxane hydrochloride (2mg/kg, ip) for morphine withdrawal. Clonidine which is an alpha-2 adrenoceptor agonist was administered in doses of 1 & 2 ug/0.5ul to lateral paragigantocellularis 5 minutes before naloxane injection. Number of chewing, jumping, standing on feet, ejaculation, Paw tremor, and defecating were evaluated half an hour after naloxane injection. The results showed that clonidine decreased the number of chewing, paw tremor and ptosis time, but had no effect on teeth gnashing, grooming and wet dog shakes. It can be proposed that alpha-2 adrenocepors in LPGi could mediate clonidine effects on withdrawal syndrome.