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S Renaud

Publications and source records attributed to S Renaud.

At least 127 records · Page 7Linked to original sources
PubMed1974

Activation of Hageman factor and initiation of hepatic vein thrombosis in the hyperlipemic rat.

Hepatic vein thrombosis initiated by an intravenous injection of endotoxin (Salmonella typhosa, 0.3 mg/kg) resulted in an incidence of 78% in rats fed a butter-rich diet (group 1). On the other hand, no lesion could be produced in control animals fed corn oil (group 2) or standard chow (group 3). In regard to the respective thrombotic tendencies, the rats fed butter showed higher circulating levels of factor XII (175% vs 140% in group 2 and 100% in group 3) and a far more severe decrease in this factor (41% vs 15% in group 2 and 7% in group 3) and in platelets (48% vs 25% in group 2 and 19% in group 3) 2 hours after the injection of endotoxin. The triggering effect of endotoxin could be reproduced by ellagic acid, a known activator of factor XII. Given by slow infusion (1 mg/kg/min) this chemical induced hepatic vein thrombosis in 52% of the rats fed the butter-rich diet. Furthermore, inhibition of factor XII activation by lysozyme (20 mg/kg/min) completely prevented hepatic vein thrombosis initiated by endotoxin in butter-fed animals. It is concluded that, in addition to the potent hypercoagulability induced by the fat-rich diets, activation of Hageman factor consecutive to endotoxin injection is essential for production of the phenomenon of hepatic vein thrombosis.

Animals↗
PubMed1974

On the mechanisms responsible for selection of hepatic veins as target for thrombosis following injection of endotoxin in hyperlipemic rats.

The feeding of a butter-rich diet, to sensitize rats for studying the phenomenon of hepatic vein thrombosis, is shown to produce severe liver steatosis leading to a sinusoidal barrage and portal hypertension. The portal pressure in these animals was 210 +/- 4 mm of saline, as compared to 113 +/- 3 mm in the normal rat. Blood circulation studies using carbon suspensions revealed production of a vascular stasis in the hepatic veins after 60 to 90 minutes, when endotoxin (Salmonella typhosa, 0.3 mg/kg) is introduced into the blood circulation to initiate hepatic vein thrombosis. Similar results were observed after 15 minutes with ellagic acid (1 mg/kg/min). The stasis was found in connection with an additional intrahepatic resistance to blood flow as evidenced by a rise in portal pressure and by a reduction in liver perfusion in relation with development of systemic hypotension. In contrast with this, endotoxin initiated only slight and transient changes in the normal rat. Thrombosis immediately followed production of stasis in the hepatic vein, whether the phenomenon was initiated by endotoxin or ellagic acid. Furthermore, inhibition of the vascular stasis of alpha-adrenergic blockade (phenoxybenzamine, 3 mg/kg) was accompanied by prevention of hepatic vein thrombosis. It is concluded that stasis in the hepatic veins resulting from a mechanical obstruction of the circulation by steatosis and by an additional reduction in blood flow initiated by endotoxin, is responsible for selection of hepatic veins as targets for thrombosis following injection of endotoxin in hyperlipemic rats.

Animals↗
PubMed1970

Thrombosis prevention by acetylsalicylic acid in hyperlipemic rats.

In rats, administration of acetylsalicylic acid (ASA) by stomach tube two hours before blood removal, or addition of the drug to platelet-rich plasma in vitro, markedly inhibited platelet aggregation induced by thrombin, ADP and collagen. Addition of ASA in vitro to human platelet-rich plasma also inhibited platelet aggregation by thrombin, ADP and collagen. In hyperlipemic rats, ASA (100 to 200 mg./kg.), administered by stomach tube once or five times, markedly inhibited the production of thrombosis initiated by intravenous injection of S. typhosa endotoxin. In these experiments, thrombosis prevention by ASA was associated with both a decrease in platelet aggregation and an increase in the recalcification plasma clotting time.

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