An animal model for the study of arterial thrombosis

1. Thrombus formations induced by electrical stimulation of the carotid artery was investigated in anesthetized rabbits and rats. Occlusive Grade III thrombi were produced consistently in 34 normal Nwe Zealand rabbits and 58 untreated albino Wistar rats. Thrombus formation was monitored continously in sosme of the animals with a magnetic flowmwter or a thermistor probe applied on the carotid. 2. The usefulnes of the model for the screeening of drugs was tested by treating the animals with warfarin, heparin, prostacyclin (PGI2), dihydroprostacyclin (DiHPGI2), prostaglandin E1(PGE), and prostaglandin D2(PGD2). 3. All of the drugs except warfarin were infused continuously into the venous circulation during the entire experimental period at a rate of 0.2 ml/min. 4. Warfarin (10 mg/Kg), administered by gavage 24 h before the experimental, prevented thrombus formation, as did heparin iv (34 U/Kg). 5. Of the foru platelet antiaggregatory prostaglandins tested, PGI2 was the most potent inhibitor of thrombus formation and DiHPGI2 the least active, as evaluted by visual inspection of stimulated arterial segments whic were excised 30 min (rabbits) or 15 min (rats) after the stimulation was stopped. PGI2 wss less active inrats than in rabbits (Thershold Protective Dose ratio ca. 4:1). PGE1 and PGD2 showed intermediate activity in both animal models

Protective action of cold acclimatization against carbon tetrachloride and ethionine-induced fatty livers.

A aclimatacao de camundongos a baixas temperaturas por um periodo maior que duas semanas previne a deposicao de lipidios no figado que se obtem pela administracao de tetracloreto de carbono e etionina