Intrathecal morphine suppresses immune function in rats with inflammatory-induced pain.

Journal Article (Journal Article)

Acute and chronic systemic administration of morphine is known to suppress immune function; however, the effect of chronic intrathecal (IT) morphine on immune function in inflammatory-induced pain is still unclear. This study examined the effects on the immune system of IT morphine in rats with formalin-induced pain. Lumbar IT catheters were implanted in rats and saline or 2.5, 5.0 or 10.0 microg/h morphine were administered for 7 days. On the last day, formalin-induced inflammatory pain was induced in rat hind paws and pain intensity was assessed. Rat spleens were then harvested for immune function assay. The IT morphine induced a dose-dependent analgesic effect and lactic acid dehydrogenase release assay showed dose-dependent suppression of natural killer cell activity. Concanavalin-A-induced splenocyte proliferation assay showed IT morphine to suppress T lymphocyte function in a dose-dependent manner. Flow cytometry showed IT morphine significantly to decrease T lymphocyte function and the percentages of T lymphocyte subsets in a dose-dependent manner. Hence, in inflammatory-induced pain IT morphine was found to suppress immune function. Chronic IT morphine should be used cautiously to treat chronic pain in immunocompromised cases.

Full Text

Duke Authors

Cited Authors

  • Zou, W; Guo, Q; Wang, E; Cai, J; Cheng, Z

Published Date

  • September 2007

Published In

Volume / Issue

  • 35 / 5

Start / End Page

  • 626 - 636

PubMed ID

  • 17900402

International Standard Serial Number (ISSN)

  • 0300-0605

Digital Object Identifier (DOI)

  • 10.1177/147323000703500507


  • eng

Conference Location

  • England