Expression of fibrinogen receptors on platelets of uremic patients is correlated with the content of GPIIb and plasma level of creatinine.
Platelets of uremic patients, activated with ADP, exposed less fibrinogen receptors than control platelets, i.e. 24612 +/- 5541 and 33400 +/- 4302 receptors per platelet, respectively. However, this difference was not statistically significant. When compared with the total number of GPIIb/IIIa complexes, quantified from platelet glycoprotein IIb (GPIIb) contents, active receptors on the platelet surface represented 13.6% and 35.1% of total pool of fibrinogen receptors in uremic and control platelets, respectively. The number of exposed fibrinogen receptors was positively correlated with the amount of GPIIb copies in both uremic and normal platelets. In uremic platelets, both the number of exposed receptors and the number of GPIIb copies were correlated with the plasma creatinine concentration suggesting, that binding of fibrinogen to uremic platelets depends upon the degree of renal failure. Uremic platelets contain similar amounts of fibrinogen as control ones i.e. 13.2 +/- 2.3 micrograms and 17.6 +/- 2.2 micrograms per 1 x 10(8) platelets, respectively. Whereas for beta-thromboglobulin (beta-TG) there was a significant difference of 392 +/- 102 ng and 803 +/- 202 ng per 1 x 10(8) platelets, respectively. Reduced beta-TG content in uremic platelets suggests limited platelet activation in vivo. These results support the concept that uremic platelets have impaired functions and indicate that there is a relationship between the progression in renal failure and disability of platelets in thrombosis.
Walkowiak
B
B
Department of Biophysics, Medical University of Lodz, Poland.
Pawlowska
Z
Z
Michalak
E
E
Cierniewski
C S
CS
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000328:Adult; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D003404:Creatinine / Q000097:blood; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D015539:Platelet Activation / Q000502:physiology; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism*; D014511:Uremia / Q000097:blood*; D001620:beta-Thromboglobulin / Q000378:metabolism
D010980:Platelet Membrane Glycoproteins; D001620:beta-Thromboglobulin; D000244:Adenosine Diphosphate; D005340:Fibrinogen; D003404:Creatinine