| First Author | Bianchi M | Year | 1999 |
| Journal | Eur J Neurosci | Volume | 11 |
| Issue | 5 | Pages | 1501-7 |
| PubMed ID | 10215902 | Mgi Jnum | J:89398 |
| Mgi Id | MGI:3040108 | Doi | 10.1046/j.1460-9568.1999.00563.x |
| Citation | Bianchi M, et al. (1999) Presence of a reduced opioid response in interleukin-6 knock out mice. Eur J Neurosci 11(5):1501-7 |
| abstractText | Cytokines are known to influence neuronal functions. The purpose of this study was to investigate the putative role of the cytokine interleukin-6 (IL-6) in the pathways involved in opioid-mediated responses, by using IL-6-deficient mice. We reported that with a thermal stimulus IL-6-knock-out (IL-6KO) mice presented nociceptive thresholds similar to those measured in their controls. However, they showed a reduced analgesic response both to the restraint stress and to the administration of low doses of morphine. Hypothalamic levels of the opioid peptide beta-endorphin were significantly higher in IL-6KO mice than they were in their controls. The development of tolerance to the analgesic effect of morphine was more rapid in IL-6-deficient mice than in wild-type controls. Binding experiments showed that the number of opioid receptors in the midbrain, but not in the hypothalamus, decreased in IL-6KO mice. Autoradiographic binding analysis revealed that the density of mu receptors diminished while the delta-opioid receptors did not. These results suggest that IL-6 is necessary for a correct development of neuronal mechanisms involved in the response to both endogenous and exogenous opiates. |
