Somatostatin receptors on human lymphocytes and leukaemia cells.
Receptors for somatostatin were identified on mitogen-activated human peripheral blood lymphocytes (PBL) and human leukaemic cells in 87.5% of lymphoblastic leukaemia and in 12.5% of non-lymphocytic leukaemia, using a somatostatin radiobinding assay. The specific binding of 125I-somatostatin of these cells increased linearly with the cell numbers and was suppressed by non-iodinated somatostatin. We investigated the distribution of fluorescent somatostatin to mitogen-activated PBL by using a fluorescence-activated cell sorter (FACS). Over 95% of the cell populations bound fluorescent somatostatin and no distinct predilection was found among certain lymphocyte subpopulations and somatostatin receptor-positive cells. Scatchard analysis showed a single class (low affinity) of binding site on mitogen-activated PBL and two classes (high and low affinity) of specific binding sites on lymphoblastic leukaemia cells.
Hiruma
K
K
Second Department of Internal Medicine, Chiba University School of Medicine, Japan.
Koike
T
T
Nakamura
H
H
Sumida
T
T
Maeda
T
T
Tomioka
H
H
Yoshida
S
S
Fujita
T
T
D002469:Cell Separation; D002478:Cells, Cultured; D004912:Erythrocytes / Q000378:metabolism; D005434:Flow Cytometry; D006098:Granulocytes / Q000378:metabolism; D006801:Humans; D007938:Leukemia / Q000097:blood*; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000378:metabolism*; D010835:Phytohemagglutinins / Q000276:immunology; D017981:Receptors, Neurotransmitter / Q000032:analysis*; D017481:Receptors, Somatostatin
D010835:Phytohemagglutinins; D017981:Receptors, Neurotransmitter; D017481:Receptors, Somatostatin