Increase of intracellular Ca2+ concentration by Vibrio vulnificus cytolysin in rat platelets; triggering mechanism of platelet cytolysis .
- Author:
Jin Bong PARK
1
;
Soo Wan CHAE
Author Information
1. Department of Pharmacology, Chonbuk National University Medical School, Chonju, 560-182 South Korea.
- Publication Type:Original Article
- Keywords:
Ethanol;
Phosphate uptake;
Glucose uptake;
Brush-border membrane vesicles;
Rabbit kidney
- MeSH:
Animals;
Blood Platelets*;
Calcium;
Cations, Divalent;
Egtazic Acid;
Ethanol;
L-Lactate Dehydrogenase;
Lanthanum;
Mefenamic Acid;
Perforin*;
Raffinose;
Rats*;
Sucrose;
Thrombocytopenia;
Verapamil;
Vibrio vulnificus*;
Vibrio*
- From:The Korean Journal of Physiology and Pharmacology
1999;3(2):199-205
- CountryRepublic of Korea
- Language:English
-
Abstract:
Vibrio vulnificus cytolysin caused platelet cytolysis and increased intracellular calcium concentration ((Ca2+))i) of rat platelets in a concentration-dependent manner. In the presence of V. vulnificus cytolysin (3 HU/ml), lactate dehydrogenase (LDH) activity was increased from 1.3+/-0.4% of control to 64.3+/-3.4% in platelet suspension buffer. In Ca2+-free platelet suspension buffer, however, V. vulnificus cytolysin did not induce (Ca2+)i increase and LDH release. Addition of EGTA (2 mM) to suspension buffer after the initial Ca2+ influx reversed (Ca2+)i to the control level. However, a Ca2+ channel blocker verapamil (20 muM) or mefenamic acid (20 muM) did not inhibit V. vulnificus cytolysin-induced (Ca2+)i increase and LDH release. Divalent cations such as Co2+, Cd2+ or Mn2+ (2 mM each) also did not alter V. vulnificus cytolysin-induced (Ca2+)i increase and LDH release. V. vulnificus cytolysin (3 HU/ml)-induced calcium influx was completely blocked by lanthanum (2 mM). Lanthanum (2 mM) also completely blocked V. vulnificus cytolysin (3 HU/ml)-induced LDH release. Osmotic protectants such as, raffinose, sucrose or PEG600 (50 mM each) did not inhibit the lytic activity of V. vulnificus cytolysin. In conclusion, lanthanum sensitive Ca2+ influx plays a significant role in Vibrio vulnificus cytolysin-induced platelet cytolysis and thrombocytopenia in V. vulnificus infection.
