Abstract:

To investigate the effects of purine nucleotides compensation on the withdrawal symptoms，contents of 5-hydroxytryptamine（5-HT），5-hydroxyindoleaceticacid （5-HIAA）and their  potential mechanisims.Methods 
 Rats were administered with heroin by intraperitoneal injection with increasing dose to develop addiction models．One hundred and ten male Wistar rats were divided into five groups：control group (C)，heroin group (H)，heroin plus purine mononucleotides (AMP+GMP，equal mole mixture) group (HAG)，heroin plus adenosine monophosphate (AMP) group (HA)，heroin plus guanosine monophosphate (GMP) group (HG).The contents of 5-HT and 5-HIAA were analyzed by fluorospectrophotometry.The content of tryptophan hydroxylase (TPH) was detected by ELISA. The expression of TPH protein was detected by immnunohistochemistry.Eight  rats from each group were used for the observation of acute withdrawal symptoms induced by naloxone at 4 h after drug administration on the 10 th day, four  rats from each group were used for immunohistochemistry.
Results  Withdrawal symptoms were alleviated in HAG，HA and HG groups (P<0.05). The contents of 5-HT and 5-HIAA in H group were significantly decreased compared with C group (P<0.05).While in HAG，HA and HG groups，the contents of 5-HT and 5-HIAA were increased when compared with H group (P<0.05).The TPH content was decreased in H group when compared with C group (P<0.05)； in HAG，HA and HG groups，the TPH contents were increased when compared with H group (P<0.05)；the expression of TPH protein was decreased in H group when compared with C group (P<0.05)，and it was increased in HAG，HA and HG groups when compared with H group (P<0.05).
Conclusion  Purine nucleotides can partly alleviate withdrawal symptoms and increase the contents of 5-HT and TPH in heroin dependent rats.

Key words: purine nucleotides；heroin；serotonin；5-hydroxyindoleacetic acid；tryptophan hydroxylase