Effect of TSH and anti-TSH receptor antibodies on the plasma membrane potential of polymorphonuclear granulocytes.
Effects of thyrotropin hormone (TSH) and anti-TSH receptor antibodies on the plasma membrane potential of polymorphonuclear granulocytes (PMN) were analyzed by means of flow cytometry. Both TSH and the autoantibody caused a rapid, dose-dependent hyperpolarization of the plasma membrane of PMNs. TSH was also able to mask (revert) the depolarizing effect of a chemotactic peptide, fMLP, on PMNs. No detectable rise in the cytosolic free calcium level accompanied the observed hyperpolarization. Quinine, a blocker of Ca(2+)-activated and voltage-gated K+ channels did not affect the hyperpolarization by TSH and antibodies. Decreasing the [K+] gradient across the plasma membrane by valinomycin, however, blocked the hyperpolarizing effect. Peptide362-376 (derived from the extracellular domain of TSH receptor) also blocked the hyperpolarization induced by both TSH and anti-TSHR antibodies. These data suggest that the observed hyperpolarization is a specific, receptor-mediated early signal during interaction of PMNs with TSH or anti-TSHR antibodies.
Kiss
E
E
Department of Biophysics, University Medical School of Debrecen, Hungary.
Balázs
C
C
Bene
L
L
Damjanovich
S
S
Matkó
J
J
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000378:metabolism; D001323:Autoantibodies / Q000276:immunology / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000648:ultrastructure; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D005454:Fluorescence Polarization; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects* / Q000276:immunology; D008969:Molecular Sequence Data; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects* / Q000276:immunology / Q000502:physiology; D009842:Oligopeptides / Q000737:chemistry / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects; D011803:Quinine / Q000494:pharmacology; D011989:Receptors, Thyrotropin / Q000276:immunology; D013972:Thyrotropin / Q000494:pharmacology*; D014634:Valinomycin / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D009842:Oligopeptides; D015221:Potassium Channels; D011989:Receptors, Thyrotropin; D014634:Valinomycin; D009240:N-Formylmethionine Leucyl-Phenylalanine; D013972:Thyrotropin; D011803:Quinine; D002118:Calcium