Contact Activation of Blood Coagulation: Trigger Properties and Hysteresis Hypothesis: Kinetic Recognition of Foreign Surfaces upon Contact Activation of Blood Coagulation: A Hypothesis
✍ Scribed by A.V. Pokhilko; F.I. Ataullakhanov
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 177 KB
- Volume
- 191
- Category
- Article
- ISSN
- 0022-5193
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✦ Synopsis
A mathematical model of contact activation of blood coagulation was developed and analysed. The model variables are concentrations of factor XIIa, kallikrein and activated high-molecular-weight kininogen. Concentrations of active factors were shown to depend on the activating signal value in a hysteretic manner. Within a range of relatively small signals, two (activated and non-activated) stable states coexist (bistability). Signals of the natural environment (surfaces of endothelial and blood cells) seem to be in the range of bistability; therefore, contact activation that persists for a short time can induce a transition of the system to the activated state, and, correspondingly, the formation of a clot. The system cannot return to the initial state, which is characterized by low activation levels, until the activating signals decrease significantly below those present in the circulation.