Differential neurotoxicity of etorphine-like opiates: lack of correlation with their ability to activate opiate receptors.
The present study was undertaken to compare the neurotoxic effects of three etorphine-like opiates (etorphine, dihydroetorphine, and another derivative of oripavine) and heroin with their ability to activate opiate receptors in human neuroblastoma cell line SK-N-SH as well as in two other neuronal cell lines. Neurotoxicity was measured by using [3H]-thymidine incorporation analysis, cell viability measurement and Cytosensor microphysiometry. It was found that, in spite of the very similar molecular structures of these opiates, they displayed significant differences in cytotoxicity, with etorphine and another derivative of oripavine possessing high potency but dihydroetorphine and heroin little effect. However, neurotoxic potency of the opiates was not directly correlated to their ability to activate opioid receptors, as determined by [35S]-guanylyl-5'-O-(gamma-tho)-triphosphate binding assay. These findings provide clear evidence of differential neurotoxicity of etorphine-like opiates, and suggest that the neurotoxicity is not closely related to the molecular configuration required as opioid receptor agonist but is probably associated with the presence of a double bond in the structure.
Ren
X H
XH
Shanghai Institute of Cell Biology, Chinese Academy of Sciences.
Zhao
J
J
Pu
L
L
Ling
K
K
Yin
D L
DL
Pei
G
G
D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D005048:Etorphine / Q000031:analogs & derivatives / Q000633:toxicity*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000737:chemistry; D003932:Heroin / Q000633:toxicity*; D006801:Humans; D009294:Narcotics / Q000633:toxicity*; D009447:Neuroblastoma; D009498:Neurotoxins / Q000633:toxicity*; D016716:PC12 Cells; D051381:Rats; D011957:Receptors, Opioid / Q000187:drug effects*; D013329:Structure-Activity Relationship; D013797:Thebaine / Q000031:analogs & derivatives / Q000633:toxicity; D014407:Tumor Cells, Cultured
D009294:Narcotics; D009498:Neurotoxins; D011957:Receptors, Opioid; D013797:Thebaine; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D005048:Etorphine; C005283:oripavine; D003932:Heroin; C034765:18,19-dihydroetorphine