Characterization of kappa-opioid receptor transcripts expressed by T cellsand macrophages

We have found that the immature T cell lines R1.1 and DPK and the macrophag e lines P388D(1) and WEHI-S also express K-opioid receptor (KOR) mRNA. Char acterization of the KOR transcripts in both brain tissue and these T cells has revealed both the normal full-length as well as a truncated form of the mRNA. Our results show that the truncated transcript lacks the second exon . Primary macrophages express this truncated form of the transcript in the absence of detectable levels of the full-length form. These results suggest a degree of heterogeneity in the expression of the opioid receptors which has not previously been reported. (C) 1998 Elsevier Science B.V. All rights reserved.