Twenty-two casts of either sex were anesthesized with urethan, and their respiration, carotid arterial pressure (BP) and ECG were recorded.6 of the 22 cats were given trilobine iv of different doses of 1.25, 2.5,5.0, 10.0, 20.0mg/kg. It was found that all the dosage levels of trilobine produced a fall in blood pressure ranging from 30 to 60 mmHg. The extent of the hypo-tensive effect seems to be dose-dependent.The other 16 cats were divided into 3 groups and used to analyse the mechanism of the hypotensive action of trilobine.The first group (6 cats) was treated with the cholinergic M-receptor blokage-atropine, adrenergic ?-receptor blokage-propranol, ganglionic biokage-C6, and section of bilateral vagus nerve.The second group (5 cats) was treated with the adrenergic ?-receptor agonist-noradrenaline.The third group (5 cats) was treated with the histaminergic H1, H2-receptor blokage-diphenhydramine, cimetidine.The experimental results indicated that all of the above treatments had no influence on the hypotensive effect of trilobine, suggesting that the mechanism of hypotensive effect of trilobine may not relate to the cholinergic M, N receptor,the adrenergic ?, ? receptor, the histaminergic H1,H2 receptor and the vagus nerves.It is possible that a direct action on blood vessel may be involved.

Five non-anesthetized dogs were intravenously infused with 4% pyrithione at a constant rate of 2 ml per minute for 5 min.During the course of treatment,experimental animals had salivation, nausea, vomiting, urination and defecation. In according with the accumulation of infused drug,the symptoms got worse and worse progressively. Finally, convulsion and respiratory failure appeared and death occured due to heart arrest. One hour after infusion and just before death, the concentration of pyrithione in the blood was 341? 180?g/ml and 657?158?g/ml respectively.The average accumulative lethal dose of pyrithione by intravenous infusion was 0.77?0.07 g/kg for dogs.

Effect of China-made isocrystal pirenzepine ( IPRZ ) on experimental ulcer produced by reserpine in rats was studied & the antiulcer effect of China-made IPRZ was compared with that of China-made PRZ. Our results showed that China-made IPRZ given by either sc ( 25-100 mg/kg ) or ig ( 25-100 mg/kg ) exerted a marked antiulcer effect on reserpine-induced gastric ulcer in rats.The antiulcer effect was increased with the increase of dose of China-made IPRZ. When China-made IPRZ was given by sc, its antiulcer effect was as potent as China-made PRZ, but when it was given by ig, its antiulcer effect was lower than China-made PRZ .This result suggest that the bioavailabili-ty of China-made IPRZ given by ig was lower than China-made PRZ.