title: Lipid and membrane fluidity abnormalities in platelets and megakaryocytes of the hereditary macrothrombocytopenic Wistar Furth rat.
abstract: Biochemical and functional abnormalities of megakaryocytes and platelets were studied in Wistar Furth (WF) rats which have genetically determined macrothrombocytopenia and megakaryocytopenia, and were compared with their counterparts in Sprague-Dawley (SD) rats. Both megakaryocytes and platelets synthesized phospholipids from [14C]acetate. WF and SD megakaryocytes incorporated 0.27 and 0.29 nmol acetate per 10(6) cells, respectively. Phosphatidylcholine (PC) accounted for 64% and 58% of the PL radioactive label in megakaryocytes of SD and WF rats, respectively, (P less than 0.05), while 69% of labeled activity was associated with PC of SD platelets compared to 60% found in PC of WF platelets (P less than 0.01). In WF platelets a significant increase in the levels of lysophosphatidylcholine (6.1% vs. 3.0%) was observed. WF platelets had substantially higher levels of esterified cholesterol, triglycerides, ceramides and a 3-fold increase in the total protein per platelet compared to SD platelets. The fatty acid composition of WF platelet PC showed quantitative abnormalities. Plasma lecithin-cholesterol acyl transferase activity and platelet function monitored by the uptake and release of [14C] serotonin showed nonsignificant variations between SD and WF rats. Compared with the control, platelet membrane fluidity, measured by fluorescence polarization using platelets labeled with 1,6-diphenyl-1,3,5-hexatriene, was significantly decreased in the WF rats.
authors.affiliation: Lawrence Berkeley Laboratory, University of California, Berkeley 94720.
authors.forename: K B
authors.initials: KB
authors.lastname: Dalal
authors.forename: R M
authors.initials: RM
authors.lastname: Leven
authors.forename: T
authors.initials: T
authors.lastname: Yee
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D005454:Fluorescence Polarization; D008533:Megakaryocytes / Q000378:metabolism*; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000378:metabolism*; D010743:Phospholipids / Q000096:biosynthesis / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011920:Rats, Inbred WF; D013921:Thrombocytopenia / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
chemical_list: D005227:Fatty Acids; D008563:Membrane Lipids; D010743:Phospholipids; D003094:Collagen