Thromb Haemost 1994; 72(01): 113-118
DOI: 10.1055/s-0038-1648821
Original Article
Schattauer GmbH Stuttgart

The Significant Enhancement of Fibrinolysis by Calcium Ion in a Cell Free System: The Shortening of Euglobulin Clot Lysis Time by Calcium Ion

Yumi Kojima
Hamamatsu University School of Medicine, Hamamatsu-shi, Shizuoka-ken, Japan
,
Tetsumei Urano
1   Departments of Internal Medicine and Physiology, Hamamatsu-shi, Shizuoka-ken, Japan
,
Kazuhisa Kojima
1   Departments of Internal Medicine and Physiology, Hamamatsu-shi, Shizuoka-ken, Japan
,
Kiyohito Serizawa
1   Departments of Internal Medicine and Physiology, Hamamatsu-shi, Shizuoka-ken, Japan
,
Yumiko Takada
1   Departments of Internal Medicine and Physiology, Hamamatsu-shi, Shizuoka-ken, Japan
,
Akikazu Takada
1   Departments of Internal Medicine and Physiology, Hamamatsu-shi, Shizuoka-ken, Japan
› Author Affiliations
Further Information

Publication History

Received 03 December 1993

Accepted after revision 10 March 1994

Publication Date:
12 July 2018 (online)

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Summary

We investigated the roles of calcium ion (Ca2+) on euglobulin clot lysis time (ECLT) and found that the physiological concentration of Ca2+ significantly (4-5 times) shortened ECLT. The shortening was observed at the concentration of Ca2+ higher than 1.5-2.0 mM. Other divalent cations such as Mg2+, Zn2+ or Mn2+ didn’t change ECLT. Anti-tPA antibody or plasminogen activator inhibitor-1 prolonged ECLT in the absence of Ca2+, whereas they had no effect on ECLT shortened by Ca2+. Cl inactivator also had no effect. When barium absorbed plasma was employed, the shortening of ECLT by Ca2+ wasn’t observed, whereas it was recovered by the readdition of barium absorbed fraction. When factor X deficient plasma was employed, the shortening of ECLT by Ca2+ was also not observed. Thus, Ca2+ enhances fibrinolysis in a cell free system by a novel pathway in which the presence of factor X is prerequisite.