Aim: To study the effect of methionine-enkephalin (met-enk) on the production and gene expression of interleukin-6 (IL-6) both in vivo and in vitro.
Methods: IL-6 was assayed using its dependent cell line MH60.BSF2 and measured by MTT spectrophotometry. IL-6 gene expression was proceeded by RNA isolation and hybridization with IL-6 cDNA.
Results: Met-enk stimulated IL-6 mRNA expression and increased its stability. Met-enk 0.1 and 1 mg.kg-1 ip for 6 d enhanced serum IL-6 levels.
Conclusion: An up-regulation of IL-6 by met-enk was mediated through an increase in transcriptional activity and stability of IL-6 mRNA.