Experiments on the action of drugs on arterial blood pressure in rabbits
Experiments on the action of drugs on arterial blood pressure in rabbits
This experiment is from the official website of Zhejiang University Fine Courses
Operation method
Experiments on the action of drugs on arterial blood pressure in rabbits
Principle
Blood pressure formation is related to three basic factors: ventricular ejection, vascular resistance, and circulating blood volume, and normal blood pressure is maintained through neurohumoral regulatory mechanisms. Efferent neuromedicines are a large class of drugs that either mimic or antagonize neurotransmitters and affect myocardial contractility, the degree of vasodilatation, and thus raise or lower blood pressure by agonizing or blocking adrenergic or cholinergic receptors distributed throughout the cardiovascular system.
Materials and Instruments
Rabbit Ethyl carbamate Heparin sodium Epinephrine hydrochloride Norepinephrine bitartrate Isoprenaline sulfate Phentolamine propranolol hydrochloride Acetylcholine acetylcholine acetylcholine atropine sulfate Atropine; Pressure transducer Bio-signal Acquisition and Processing System Move 1. Experimental system connection and system parameterization For more product details, please visit Aladdin Scientific website.
(1) Instrument connection Carotid blood pressure measurement and recording device. Fix the blood pressure transducer on the iron pillar, its position should be on the same level with the heart. Pressure transducer output line connected to the microcomputer biological signal processing system input channel.
(2) Instrument parameter setting
① RM6240 system: pressure transducer input channel mode for blood pressure, time constant for DC, filter frequency 100Hz, sensitivity 12Kpa, sampling frequency 800Hz, scanning speed 500ms/div.
② PcLab and MedLab system: pressure transducer input channel name is blood pressure, channel amplification 200, DC coupling (lower limit frequency DC), upper limit frequency 30Hz, sampling interval 2ms.
2. Anesthesia and surgery for animals
(1) Intravenous anesthesia Rabbits were anesthetized by intravenous injection of 20% urethane at a dose of 1g/kg body weight at the ear margin. After the rabbit was anesthetized, it was placed on its back and the limbs and head were fixed successively.
(2) Neck surgery The rabbit's hair was clipped off at the front of the neck, the skin was incised in the middle for 5-6 cm, and the soft tissues and neck muscles were separated longitudinally with hemostatic forceps to expose the trachea and the nerve sheaths of the right blood vessels parallel to the trachea, and the left common carotid artery was carefully placed with two fine wires underneath the left common carotid artery, ligated with the distal end of the artery (as high as possible) and an arterial clip was attached to the proximal end of the artery to block the flow of blood. A V-shaped incision was made in the artery below the ligature with ophthalmic scissors, and an arterial cannula filled with saline and heparin connected to a pressure transducer was inserted into the carotid artery in the direction of the heart and secured with a wire, the arterial clip was opened, and the blood pressure was recorded.
(3) Rabbit ear vein drug delivery device The other end of the scalpel needle connected to the silicone tube was connected to a No. 9 needle and loaded onto a 10 ml syringe, which was filled with saline, and then stabbed into the rabbit's ear vein with the tip of the scalpel needle. And fixed with adhesive tape.
After the above steps were ready the normal blood pressure curve was recorded and then the following drugs were given sequentially from the vein.