Uric acid, indole-3-acetic acid (IA), and indoxyl sulfate (IS) increase thrombogenicity and recapitulate the effect of uremic serum. A, Ex vivo thrombogenicity of uric acid on vascular smooth muscle cell (vSMC)–coated flow loop model. Top, vSMCs exposed to uric acid for 24 hours. The tubes were then subjected to the flow loop system. A representative visual examination of clot is shown. Bottom, Hemoglobin and lactate dehydrogenase (LDH) values of the thrombus from the tubes treated with uric acid and NaOH are shown. Mean of 9 tubes is shown. *Hemoglobin P<0.001 and LDH P<0.001 for uric acid compared with NaOH. Hemoglobin and LDH values of thrombus from the uric acid–exposed tubes pretreated with control (control aB) or anti-TF neutralizing (aTF) antibody are also shown. Mean of 6 tubes is shown. #P<0.01 for hemoglobin and P<0.02 for LDH of aTF compared with control antibody. Error bars=SEM. B, Ex vivo thrombogenicity of IA on vSMC-coated flow loop model. Top, vSMCs treated with IA and for 24 hours were subjected to flow loop. A representative visual examination of clot is shown. Bottom, Hemoglobin and LDH values of the thrombus from the tubes treated with IA and human serum albumin (control) are shown. Mean of 9 tubes is shown. *Hemoglobin P<0.05 and LDH P<0.05 for IA compared with human serum albumin. Hemoglobin and LDH values of thrombus from the IA-exposed tubes pretreated with control antibody or aTF antibody are also shown. Mean of 6 tubes. #P<0.05 for hemoglobin and P<0.05 for LDH for aTF compared with control antibody. Error bars=SEM. C, IS-induced thrombus was significantly inhibited by surface TF neutralization. Top, vSMCs treated with IA for 24 hours were subjected to flow loop. A representative visual examination of clot is shown. Bottom, Hemoglobin and LDH values of the thrombus from the tubes treated with IS and human serum albumin (control) are shown. Mean of 9 tubes is shown. *Hemoglobin P<0.05 and LDH P<0.05 for IA compared with human serum albumin. Hemoglobin and LDH values of thrombus from the IS-exposed tubes pretreated with control antibody or aTF antibody are also shown. Mean of 6 tubes is shown. #P<0.05 for hemoglobin and P<0.05 for LDH for aTF compared with control antibody. Error bars=SEM.