title: Inhibition of platelet aggregation and immunomodulation of NK lymphocytes by administration of ascorbic acid.
abstract: Platelets aggregation around migrating tumor cells offers protection against the cytotoxic activity of the natural killers cells (NKC). The ascorbic acid in 3 x 10(-3) M concentration completely inhibited platelet aggregation, decreased thromboxane B2 levels, and inhibited the expression of platelet membranic receptor GpIIb/IIIa in non stimulated platelets, and increased the NKC cytotoxicity in an average rate of 105, 61, and 285% in the NKC/targets cells ratios 12.5:1, 25:1 and 50:1 respectively. The results suggest the role of ascorbic acid in increasing the susceptibility of tumor cells to NKC; the ascorbic acid could be used as part of a multidrug therapy to treat diseases which up to now have been treated only through chemotherapy.
authors.affiliation: Laboratory of Physiology, Faculty of Medicine, University of Ioannina, Ioannina 45110, Greece. johntolio@hotmail.com
authors.forename: Ioannis K
authors.initials: IK
authors.lastname: Toliopoulos
authors.forename: Yannis V
authors.initials: YV
authors.lastname: Simos
authors.forename: Telemachos A
authors.initials: TA
authors.lastname: Daskalou
authors.forename: Ioannis I
authors.initials: II
authors.lastname: Verginadis
authors.forename: Angelos M
authors.initials: AM
authors.lastname: Evangelou
authors.forename: Spyros C
authors.initials: SC
authors.lastname: Karkabounas
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects / Q000276:immunology; D002470:Cell Survival / Q000187:drug effects / Q000276:immunology; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D006801:Humans; D056747:Immunomodulation / Q000187:drug effects*; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000096:biosynthesis; D013929:Thromboxane B2 / Q000037:antagonists & inhibitors / Q000096:biosynthesis
chemical_list: D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D013929:Thromboxane B2; D001205:Ascorbic Acid