Chitosan enhances platelet adhesion and aggregation.
In this study, chitosan (MW=50,000) was tested for its enhancing platelet activity in rabbit platelet suspensions and the possible mechanisms involved were further investigated. Our results showed that after initial (5 min) and long-term (30 min) contact of platelets with chitosan, the platelet adhesion to chitosan-coated microtiter plates was dose-dependently increased compared to that of solvent control. Similarly, chitosan also dose-dependently increased the platelet aggregation and the intracellular free Ca(2+) rise of Fura-2-AM loaded platelets. Additionally, in the presence of FITC-labeled anti-CD41/CD61, chitosan significantly enhanced the expression of platelet glycoprotein IIb/IIIa complex assayed by a flow cytometer. It is concluded that chitosan is an effective inducer for platelet adhesion and aggregation and the mechanisms of action of chitosan may be associated, at least partly, with the increasing [Ca(2+)](i) mobilization and enhancing expression of GPIIb/IIIa complex on platelet membrane surfaces.
Chou
Tz-Chong
TC
Department of Physiology, National Defense Medical Center, No. 161, Min-Chuan E. Rd. Sec. 6, Taipei, Taiwan, ROC. tcchou@ms5.hinet.net
Fu
Earl
E
Wu
Chang-Jer
CJ
Yeh
Jeng-Hsien
JH
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects*; D002686:Chitin / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000494:pharmacology*; D048271:Chitosan; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000494:pharmacology; D039661:Integrin beta3 / Q000096:biosynthesis; D010974:Platelet Aggregation / Q000187:drug effects*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000378:metabolism; D040201:Platelet Membrane Glycoprotein IIb / Q000096:biosynthesis; D011817:Rabbits; D013696:Temperature; D013997:Time Factors
D005456:Fluorescent Dyes; D039661:Integrin beta3; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D040201:Platelet Membrane Glycoprotein IIb; D002686:Chitin; D048271:Chitosan; D002118:Calcium