连续描记血压和通过静脉注射各种药物是生理学、药理学及针麻原理研究中常需用的方法。以往慢性实验多用间接测压法

不仅所测血压值与直接测压有一定误差

而且A method of chronically implanted arterial and veinal cannula has been established for the direct measurement of blood pressure and injecting varied drugs in unanesthetized rat. The arterial cannula is a "U"shaped polyethylene tube. The thin end is 1.5 cm long with a diameter corresponding to that of carotid artery

and the thick end is 5 cm long connected to a three-way stopcock. The rat

weighing 250-300g

was slightly anesthetized with ether. The thin end of the arterial cannula which was filled with heparinized saline (150 units/ml) was inserted into the left carotid artery. The thick end of cannula was across over the trachea

passing the skin of the neck

with the three-way stopcock fixed on the back of the rat. In order to prevent the blood coagulation

the arterial cannula was flushed every 6-10 hours with 0.5 ml (150 units/ml) of the heparinized saline solution. About 24 hours after surgery

the experiment might start. During the experiment

the arterial cannula was connected to a pressure transducer through the three-way stopcock for recording the blood pressure. In fifteen normal rats

the mean arterial blood pressure measured with this methode was 115 ±3mmHg. This result was similar to that in the litera ture. The veinal cannula is also a polyethylene tube. The fine end is 3cm long

with a diameter same as that of the femoral vein. The other end of the tube is about 4mm in diameter. After the thin end of the veinal cannula (filled with heparinized saline solution) had been inserted into the right femoral vein approximately 2cm

the other end of the cannula which was somewhat bent

passing through the groin area

was fixed on the back of the rat. The exposed end of the cannula was plugged with a stopper. During experiment

the stopper was taken off and the cannula could be connected to a syringe filled with drug solution for injection.