Muscarinic receptor subtypes in subpopulations of human blood mononuclear cells as analyzed by RT-PCR technique

Abstract

In this study we have analysed the expression of mRNA encoding the m1–m5 mAChR subtypes in human blood mononuclear cells and subpopulations of lymphocytes using reverse transcriptase-polymerase chain reaction (RT-PCR) technique. Total RNA was extracted from human blood mononuclear cells, T cells, monocytes, EB virus transformed B cells and from two leukemic cell lines and analysed by RT-PCR. Our results indicate that mRNAs for the m3, m4 and m5 muscarinic subtypes are expressed in mononuclear cells and purified T cells while m1 and m2 mRNAs were not detected in these cells. No m1–m5 subtype mRNA was detected in B cells and monocytes, indicating absence of muscarinic receptors in these cells. The expression of muscarinic subtypes in the leukemic T cell line, Peer, and the promyelocytic leukemic cell line HL-60 was different from peripheral mononuclear cells. Both m3 and m5 subtypes were expressed in Peer cells but not the m4 subtype, whereas the m4 and m5 subtypes were detected in HL-60 cells.