Mononuclear cell-membrane "fluidity": a study in some haematological malignancies.

T E Blecher,R H Bisby

doi:10.1038/bjc.1977.259

Abstract

The polarization of fluorescence from diphenyl hexatriene embedded in the membranes of intact peripheral-blood mononuclear cells has been measured and used to assess the "microviscosity" or fluidity of the membrane. Cell preparations were examined from patients with various types of leukaemia and related conditions in which circulating primitive cells may occur. Significantly lower fluorescence polarization values were obtained in all samples from patients with chronic lymphocytic leukaemia, but normal results were obtained in cases of chronic granulocytic leukaemia, myelosclerosis, solid lymphomas and in acute leukaemias in remission. In relapsed acute leukaemia, fluorescence polarization indicated reduced "microviscosity" of the cell membrane when large numbers (greater than 10(9)/1) of primitive cells were present; normal "microviscosity" was indicated when less than 10(9)/1 primitive cells were present. However, exceptions occurred in both cases, and the technique failed to give warning of imminent relapse in one case. Our findings suggest that a reduction in "microviscosity" as indicated by this technique is not a general property of the blood leucocytes in all types of leukaemia, and that the technique cannot, at present, be regarded as an alternative method for detecting circulating primitive cells.

Highlights

Summary.-The polarization of fluorescence from diphenyl hexatriene embedded in the membranes of intact peripheral-blood mononuclear cells has been measured and used to assess the "microviscosity" or fluidity of the membrane
The fluorescence polarization was related directly to the microviscosity of this region; this interpretation is believed not to be strictly correct (Chen et al, 1977) in terms of the motion of the dye within the lipid membrane. Using this technique it was reported that the "microviscosity" of mouse lymphoma cells and liposomes prepared from them is markedly lower than that of normal mouse lymphocytes and the corresponding liposomes (Shinitzky and Inbar, 1974)
The same authors have reported that the "microviscosity" of isolated surface membranes from human chronic lymphocytic leukaemia (CLL) cells was considerably less than that of normal human lymphocytes (Inbar and Shinitzky, 1974b)

Summary

Introduction

Summary.-The polarization of fluorescence from diphenyl hexatriene embedded in the membranes of intact peripheral-blood mononuclear cells has been measured and used to assess the "microviscosity" or fluidity of the membrane. The fluorescence polarization was related directly to the microviscosity of this region; this interpretation is believed not to be strictly correct (Chen et al, 1977) in terms of the motion of the dye within the lipid membrane Using this technique it was reported that the "microviscosity" of mouse lymphoma cells and liposomes prepared from them is markedly lower than that of normal mouse lymphocytes and the corresponding liposomes (Shinitzky and Inbar, 1974). These differences in apparent "microviscosity" appear to reflect mainly the lower cholesterol/phospholipid ratio in the leukaemic and lymphoma cell when compared with normal lymphocytes (Shinitzky and Inbar, 1976) Using this fluorescence polarization technique, with all-trans 1,6-diphenyl1,3,5-hexatriene (DPH) as the fluorescent probe, we have performed studies on intact peripheral-blood mononuclear-cell preparations from patients with various types of leukaemia and related conditions. BISBY of the convincing reduction in fluorescence long that remission continued thereafter

Methods

Results

Conclusion