Stereospecific modulation of tumorigenicity by opioid antagonists.
The effects of (+) and (-) isomers of naloxone in altering tumor response in A/Jax mice inoculated with S20Y neuroblastoma were determined. Mice given daily subcutaneous injections of 15 mg/kg (-)naloxone had a 71% tumor incidence, a 33% delay in the time before tumor appearance, and a 28% increase in survival time. Inoculation of neuroblastoma cells in control subjects resulted in 100% tumor incidence within 13 days. Animals given 15 mg/kg (+)naloxone were comparable to control subjects in all aspects of neural neoplasia. These results show that opioid antagonists exert a stereospecific action on neural cancers, and provide further evidence that endogenous opioid systems play an important role in neuro-oncogenic expression.
D000818:Animals; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology*; D009447:Neuroblastoma / Q000209:etiology* / Q000473:pathology; D011957:Receptors, Opioid / Q000187:drug effects; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
D009292:Narcotic Antagonists; D011957:Receptors, Opioid; D009270:Naloxone; D009020:Morphine