Mechanisms of thrombocytopenia in the acute phase of antigen-induced arthritis in rabbits.
Arthritis induced in hyperimmune rabbits by the intra-articular injection of the specific antigen was associated with a fall in circulating platelet number that lasted up to 60 days. Pretreatment of the animals with indomethacin and econazol at doses that significantly decreased thromboxane levels in the synovial fluids reduced the arthritis-related thrombocytopenia in the acute phase of arthritis. A similar inhibition was seen when L-655,240, a specific Thromboxane A2 antagonist, and BN 52021, a Platelet Activating Factor antagonist were used. The results suggest that both thromboxane and PAF are involved in the mechanisms leading to thrombocytopenia in this experimental model of arthritis.
Fernandes
A J
AJ
Department of Rheumatology, Faculty of Medicine, University of Sao Paulo, Brazil.
Calvo
I F
IF
de Falco
V
V
da Rocha
F A
FA
Sirois
P
P
Jancar
S
S
D000818:Animals; D001169:Arthritis, Experimental / Q000150:complications*; D004224:Diterpenes; D004464:Econazole / Q000627:therapeutic use; D005260:Female; D046934:Ginkgolides; D007211:Indoles / Q000627:therapeutic use; D007213:Indomethacin / Q000627:therapeutic use; D007783:Lactones / Q000627:therapeutic use; D008297:Male; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors / Q000502:physiology; D011817:Rabbits; D013582:Synovial Fluid / Q000378:metabolism; D013921:Thrombocytopenia / Q000209:etiology* / Q000517:prevention & control; D013928:Thromboxane A2 / Q000037:antagonists & inhibitors / Q000502:physiology; D013929:Thromboxane B2 / Q000502:physiology
D004224:Diterpenes; D046934:Ginkgolides; D007211:Indoles; D007783:Lactones; D010972:Platelet Activating Factor; C052517:L 655240; D013929:Thromboxane B2; D013928:Thromboxane A2; D004464:Econazole; C045856:ginkgolide B; D007213:Indomethacin