Renal dysfunction due to anturan

Effects of Y-20811, a thromboxane A2 synthetase inhibitor, on experimentally induced coronary thrombosis in anesthetized dogs

The effects of Y-20811, a selective inhibitor of thromboxane A2 (TXA2) synthetase, on blood flow and local levels of immunoreactive thromboxane B2 (i-TXB2) and 6-keto prostaglandin F1 alpha (i-6-keto PGF1 alpha) in the coronary artery were investigated in the canine model of coronary thrombosis. Thrombosis was induced by applying an electric current to the intraluminal surface of the coronary artery. The plasma levels of i-TXB2 and i-6-keto PGF1 alpha were measured distal to the electrode. In the control group, coronary blood flow decreased and finally stopped 207 +/- 53 min (mean +/- S.E.M., n = 5) after the start of current application. The level of i-TXB2 rose before the coronary occlusion. Coronary blood flow did not change significantly in the Y-20811-treated group (1 mg/kg i.v.). The level of i-TXB2 decreased and remained significantly lower than that in the control group. The level of i-6-keto PGF1 alpha tended to increase slightly in the Y-20811-treated, but not in the control group. The weight of the thrombus in the Y-20811-treated group was significantly less than that in the control group (P less than 0.01). These results suggest that Y-20811 prevents coronary thrombosis by the inhibition of TXA2 production around the electrically injured lumen of the coronary artery.

Influence of blood sampling site and technique on thromboxane concentrations in patients with ischemic heart disease

Thromboxane A2 may play a role in coronary arterial spasm, unstable angina, myocardial infarction, cardiac arrhythmias, and sudden death. Although previous studies have examined peripheral, aortic, and coronary sinus concentrations of its stable metabolite, thromboxane B2 (TxB2), it is unknown, first, if blood sampling through long catheters alters the concentration of TxB2 and second, if peripheral levels of this prostanoid reflect its intracoronary production and release. In order to answer these questions, paired blood samples were obtained through an 18-gauge needle and a No. 7 or 8 French 110 to 125 cm catheter from the arterial (14 patients) and venous (16 patients) circulations; in addition, coronary sinus and peripheral venous samples were obtained in 16 patients and aortic samples were obtained in 14 of these patients. All samples were analyzed to TxB2 by radioimmunoassay. Blood sampling through long catheters did not systematically alter the concentrations of arterial TxB2 (needle, 85.5 +/- 67.5 pg/ml [mean +/- SD]; catheter, 62.3 +/- 40.9 pg/ml; p = 0.20) or venous TxB2 (needle, 182.5 +/- 170.5 pg/ml; catheter, 521.4 +/- 1536.0 pg/ml; p = 0.39). Peripheral venous TxB2 levels did not correlate with TxB2 levels in coronary sinus (r = 0.01) or the TxB2 coronary sinus/aortic ratios (r = 0.21). Thus blood sampling through long catheters across the coronary bed is both a reliable and necessary method for assessing intracoronary TxB2 production in patients with ischemic heart disease.