title: Low intracellular calcium concentration in the platelets after stimulation in patients with myeloproliferative disorders.
abstract: Intracellular calcium levels in the platelets of patients with myeloproliferative disorders (MPD) were measured by the Aequorin method. In the patients with MPD, the maximum intracellular calcium level [Ca2+]i was significantly lower and the time required to reach the peak calcium level was significantly longer than in normal controls after thrombin (0.5 U/ml) and collagen (2.5 micrograms/ml) stimulation. The rate of increase in intracellular calcium levels after thrombin (0.5 U/ml) stimulation in the presence of various concentrations of extracellular calcium was lower than in the normal controls, which suggests that the low level of intracellular [Ca2+]i after stimulation is caused mainly by a low Ca2+ influx. These results suggest the relationship between abnormalities of membrane glycoprotein and the impaired calcium influx of MPD platelets.
authors.forename: T
authors.initials: T
authors.lastname: Fujimoto
authors.forename: K
authors.initials: K
authors.lastname: Fujimura
authors.forename: A
authors.initials: A
authors.lastname: Kuramoto
mesh_terms: D001792:Blood Platelets / Q000378:metabolism*; D002118:Calcium / Q000097:blood*; D005110:Extracellular Space / Q000378:metabolism; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000097:blood*; D008562:Membrane Glycoproteins / Q000097:blood; D011087:Polycythemia Vera / Q000097:blood*; D013920:Thrombocythemia, Essential / Q000097:blood*
chemical_list: D008562:Membrane Glycoproteins; D002118:Calcium