Effects of dietary supplementation with cod-liver oil on endothelium-dependent responses in porcine coronary arteries

To study the effect of dietary supplemntation with fish oil on endothelium-dependent responses, Yorkshire pigs were maintained on a normal diet or on a low (0.6 ml/kg/day) or a high (1.0 ml/kg/day) dose of cod-liver oil for 4 weeks. Endothelium-dependent responses were examined in vitro in rings of proximal left anterior descending coronary arteries taken from control and treated animals studied in parallel. Endothelium-dependent relaxations in response to bradykinin, serotonin, adenosine diphosphate, and thrombin were facilitated in arteries from treated but not in those from control animals, whereas the relaxations in response to A23187 were unaltered. The facilitated relaxations were not altered by indomethacin but significantly inhibited by methylene blue. Aggregating platelets from control and treated pigs induced comparable, facilitated endothelium-dependent relaxations in rings taken from treated pigs. The platelet-induced contractions were significantly reduced in rings with endothelium taken from treated pigs, and they were comparable in rings without endothelium in both groups. Aggregating platelets from control and treated pigs released comparable amounts of serotonin and thromboxane A2. Endothelium-dependent relaxations induced by arachidonic acid and eicosapentaenoic acid were unaltered, whereas transient endothelium-dependent contractions induced by arachidonic acid were significantly reduced by the treatment with cod-liver oil. Relaxations to sodium nitroprusside or isoproterenol, and contractions to potassium chloride or serotonin were not different in rings without endothelium from control or treated pigs. These results indicate that dietary supplementation with cod-liver oil facilitates endothelium-dependent relaxations and inhibits endothelium-dependent contractions in porcine coronary arteries.link_to_subscribed_fulltex

Measurement of Cross-Linked Fibrin Derivatives in Patients Undergoing Abdominal-Surgery - Use in the Diagnosis of Postoperative Venous Thrombosis

Levels of plasma crosslinked fibrin derivatives, a sensitive and direct marker of the lysis of intravascular crosslinked fibrin, were measured serially in 135 patients undergoing major abdominal surgery to determine their behavior and their use as a screening test for postoperative venous thrombosis. Preoperative levels and levels on the first postoperative day were significantly higher by both enzyme immunoassay and latex assay in 31 patients who developed venous thrombosis (positive venography) than in 104 patients who did not (negative I-125 fibrinogen leg scan). Preoperative XLFDP levels 400 ng/ml (enzyme immunoassay) had a sensitivity to the diagnosis of postoperative venous thrombosis of 58%, specificity 74%, positive predictive value 41% and negative predictive value of 85%. The sensitivity of XLFDP levels over 1200 ng/ml on the first postoperative day was 65%, specificity 73%, positive predictive value 38% and negative predictive value 89%. These cutoff values were chosen (high negative predictive value) to allow identification of patients who were unlikely to have venous thrombosis. Measurement of plasma XLFDP, a simple inexpensive test, could bc used as a screen to select patients for surveillance procedures (IPG or duplex ultrasonography). A substantial increase in XLFDP levels (> 500 ng/ml) occurred in virtually all patients, suggesting that fibrinolysis is not 'shutdown' postoperatively and that these assays reflect lytic activity at the fibrin surface more accurately than do measurements of plasminogen activators and their inhibitors