Increase of Intracellular Ca<SUP>2⁢</SUP> Concentration by <I>Vibrio Vulnificus</I> Cytolysin in Rat Platelets; Triggering Mechanism of Platelet Cytolysis
Increase of Intracellular Ca<SUP>2⁢</SUP> Concentration by <I>Vibrio Vulnificus</I> Cytolysin in Rat Platelets; Triggering Mechanism of Platelet Cytolysis
- Jin Bong Park Soo Wan Chae
- 대한생리학회-대한약리학회
- The Korean Journal of Physiology & Pharmacology
- 제3권 제2호
- 등재여부 : KCI등재
- 1999.01
- 199 - 205 (7 pages)
<P> <I> Vibrio vulnificus</I> cytolysin caused platelet cytolysis and increased intracellular calcium concentration ([Ca<SUP>2⁢]</SUP>]<SUB>i</SUB>) of rat platelets in a concentration-dependent manner. In the presence of <I>V. vulnificus</I> 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 Ca<SUP>2⁢</SUP>-free platelet suspension buffer, however, <I>V. vulnificus</I> cytolysin did not induce [Ca<SUP>2⁢</SUP>]<SUB>i</SUB> increase and LDH release. Addition of EGTA (2 mM) to suspension buffer after the initial Ca<SUP>2⁢</SUP> influx reversed [Ca<SUP>2⁢</SUP>]<SUB>i</SUB> to the control level. However, a Ca<SUP>2⁢</SUP> channel blocker verapamil (20 μM) or mefenamic acid (20 μM) did not inhibit <I>V. vulnificus </I>cytolysin-induced [Ca<SUP>2⁢</SUP>]<SUB>i</SUB> increase and LDH release. Divalent cations such as Co<SUP>2⁢</SUP>, Cd<SUP>2⁢</SUP> or Mn<SUP>2⁢</SUP> (2 mM each) also did not alter <I>V. vulnificus</I> cytolysin-induced [Ca<SUP>2⁢</SUP>]<SUB>i</SUB> increase and LDH release. <I>V. vulnificus</I> cytolysin (3 HU/ml)-induced calcium influx was completely blocked by lanthanum (2 mM). Lanthanum (2 mM) also completely blocked <I>V. vulnificus </I>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 <I>V. vulnificus</I> cytolysin. In conclusion, lanthanum sensitive Ca<SUP>2⁢</SUP> influx plays a significant role in <I>Vibrio vulnificus</I> cytolysin-induced platelet cytolysis and thrombocytopenia in <I>V. vulnificus</I> infection.