Retention of thrombin by polytetrafluoroethylene: influence on the adsorption of fibrinogen/fibrin.
Beads of polytetrafluoroethylene were used to investigate adsorption of thrombin and the influence of the adsorbed protease on a subsequent deposition of fibrinogen. Adsorption of active thrombin was not detected by a specific fluorogenic substrate unless > 0.1 units/ml had been applied. Adsorption was considerably improved by albumin, which protected soluble thrombin from inactivation by hydrophobic surfaces. Retention of active thrombin was optimal at ca. 0.1% albumin and decreased at higher concentrations. After incubation with plasma, negligible thrombin activity was detected at the polytetrafluoroethylene beads by the fluorogenic substrate. However, repeated incubation with fresh plasma samples resulted in adsorbed activity rising with each step. This result suggested that thrombin activity should also accumulate at a polytetrafluoroethylene surface in vivo if fresh blood is permanently flowing past. Adsorbed thrombin improved the subsequent retention of fibrinogen, monitored by an antibody technique. Concomitantly, fibrinopeptides A, AP and AY were slowly released whilst fibrinopeptide B was not detectable before 24 h.
Max Planck-Institut für Biochemie, Martinsried, Germany.
E
E
Schlosser
R
R
Simler
H
H
Hörmann
D000327:Adsorption; D001807:Blood Vessel Prosthesis; D005337:Fibrin / Q000378:metabolism*; D005340:Fibrinogen / Q000378:metabolism*; D006801:Humans; D010949:Plasma; D011138:Polytetrafluoroethylene / Q000737:chemistry*; D013917:Thrombin / Q000737:chemistry*
D005337:Fibrin; D005340:Fibrinogen; D011138:Polytetrafluoroethylene; D013917:Thrombin