title: Effects of hypoxia on heparan sulfate in bovine aortic and pulmonary artery endothelial cells.
abstract: Newly synthesized heparan sulfates purified from the cell layer of bovine aortic endothelial cells (BAECs) and main pulmonary artery endothelial cells (BPAECs) cultured under either normoxic (21% oxygen) or hypoxic (3% oxygen) conditions were characterized by size, charge, and capacity to bind to antithrombin III. Incorporation of radiolabeled sulfate into cell layer-associated heparan sulfate was reduced by 70% in BAECs and by 45% in BPAECs during exposure to 3% oxygen; degradation of radiolabeled heparan sulfate was not affected by hypoxia. However, the percentage of total radiolabeled heparan sulfate that bound to antithrombin III was increased by 33% for BAECs and by 120% for BPAECs when compared with radiolabeled heparan sulfate synthesized during the 21% oxygen exposure. Both the high- and low-antithrombin III affinity radiolabeled heparan sulfate consisted of two components of different sizes; the low-affinity components (mean sizes, 60 and 40 kd) generated under normoxic conditions were smaller than their respective high-affinity components (mean sizes, 70 and 55 kd) by molecular sieve chromatography. The components of low-antithrombin III affinity heparan sulfate generated during exposure to 3% oxygen were increased in size compared with the corresponding low-affinity components generated during the 21% oxygen exposure for both BPAECs and BAECs. In addition, the amount of the larger high-antithrombin III affinity component was reduced in both cell types exposed to hypoxia. There was no difference in functional heparin-like activity per dish between cells cultured at 3% and 21% oxygen; BAECs had twofold to threefold greater activity per dish than did BPAECs at both levels of oxygen.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Pulmonary Section, VA Medical Center, Boston, MA 02130.
authors.forename: J B
authors.initials: JB
authors.lastname: Karlinsky
authors.forename: S
authors.initials: S
authors.lastname: Rounds
authors.forename: H W
authors.initials: HW
authors.lastname: Farber
mesh_terms: D000818:Animals; D000990:Antithrombin III / Q000032:analysis; D001011:Aorta / Q000166:cytology* / Q000378:metabolism; D002417:Cattle; D015687:Cell Hypoxia; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D004588:Electrophoresis, Cellulose Acetate; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism; D006025:Glycosaminoglycans / Q000378:metabolism; D006497:Heparan Sulfate / Q000302:isolation & purification* / Q000378:metabolism; D010100:Oxygen / Q000008:administration & dosage; D011651:Pulmonary Artery / Q000166:cytology* / Q000378:metabolism
chemical_list: D000990:Antithrombin III; D006025:Glycosaminoglycans; D006497:Heparan Sulfate; D010100:Oxygen