Suggestive Evidence for Receptors for Morphine and Methionine-Enkephalin on Normal Human Blood T Lymphocytes

TLDR

The study investigates the effects of morphine, dextromoramide, levomoramide, and methionine‑enkephalin on normal human T lymphocytes using active and total rosette assays. The authors employed in‑vitro active and total rosette tests to assess how these compounds influence T‑cell activity. Morphine and dextromoramide reduced active T‑cell rosettes, an effect reversed by naloxone, while levomoramide had no effect; methionine‑enkephalin increased active rosettes, also naloxone‑sensitive, indicating opioid‑like receptors on T lymphocytes that may link the CNS to immunity.

Abstract

This study reports the in vitro influence of morphine, dextromoramide, levomoramide, and methionine-enkephalin upon normal human T blood lymphocytes by using the active and total rosette tests. Morphine and dextromoramide inhibited the percentage of active T rosettes. This effect was completely reversed in the presence of naloxone, their specific antagonist. The specificity was further demonstrated by the absence of the effect of levomoramide, the inactive enantiomere, upon the rosette system. Methionine-enkephalin increased the percentage of active T rosettes. This effect was specifically inhibited by naloxone. These observations suggest that normal human blood T lymphocytes bear surface receptor-like structures for morphine, dextromoramide, and methionine-enkephalin. Such findings may provide a link between the central nervous system and the immune system.