Experiments on the effect of neostigmine on the muscarinic action of succinylcholine and cylindrolysine

Myorelaxants are divided into two types: depolarizing and non-depolarizing. Succinylcholine is the representative drug of the depolarizing type of muscarinic drugs. After binding to the N2 receptor on the postsynaptic membrane at the neuromuscular junction, the drug can make the postsynaptic membrane persistently depolarized, and the receptor can no longer react to Ach, thus relaxing the skeletal muscle. The anticholinesterase drug neostigmine cannot counteract its muscarinic effect, but rather aggravates it. The representative drug of non-depolarizing muscarinic drugs is cylindrolysine, which competes with Ach for the N2 receptor in the postsynaptic membrane at the neuromuscular junction, and its muscarinic effect can be rescued by neostigmine.

Operation method

intravenous injection

Materials and Instruments

Rats
Succinylcholine chloride Neostigmine bromide Uracaine hydrochloride Saline
Powerlab mainframe Stimulator Tension transducer Surgical instruments Cotton thread Rubberized clay Tachyderm Iron table

Move

1. Install and set up the Powerlab Chart setup file for recording muscle tone; adjust the relevant parameters of the stimulator (stimulation intensity of about 2 V, stimulation interval of 990 ms, wave width of 4 ms);

2. The rats were weighed and anesthetized; 20% ursodiol was injected intraperitoneally (1.2～1.5 g/kg). After a few minutes, the reflexes disappeared and the experiment could be carried out;

3. isolate the sciatic nerve: cut the skin behind the hip joint, in the medial depression of the sciatic tuberosity, bluntly separate the muscle, expose a section of the sciatic nerve (thick white nerve), use cotton thread impregnated with procaine, tie a knot around the sciatic nerve, and do a conduction block anesthesia on the sciatic nerve trunk to exclude downstream interference.

4. Separation of the peroneal nerve: on the lateral side of the knee joint, cut the skin, bluntly separate the muscle tissue, and separate the peroneal nerve (the location is shallow, very thin, between the transverse and oblique fibers, and travels outward and downward. The deeper layer is the tibial nerve, which should not be misidentified), and the nerve is threaded for backup (in order to install stimulation electrodes here for stimulation experiments).

5. Separate the tibialis anterior muscle: fix the two forelimbs of the rat on the surgical table (supine), cut the skin of the calf upward from the anterior ankle joint of the hind limb, cut the transverse ligament at the anterior part of the ankle joint, isolate the tendon of the anterior tibialis muscle, isolate the tibialis anterior muscle along the tibia (be careful not to damage the blood vessels), ligate the anterior tibialis muscle tendon at the ankle, and cut off the tendon at the distal end of the ligature line.

6. Connection: After the surgical operation, the tibialis anterior muscle was connected to the Powerlab tension transducer, and the stimulating electrode was placed at the peroneal nerve. The optimal preload is set at approximately 10 g. After stabilizing for a period of time, the electrodes are placed at the peroneal nerve. After a period of stabilization, a normal muscle contraction curve is recorded prior to drug administration.

7. Administration 1: Tubocurarine 0.2 mg/kg body weight (0.005% tub, 0.4 ml/100 g body weight) was injected intraperitoneally, and the contraction amplitude was suppressed by 20% (the normal amplitude was taken as M, and the change of contraction amplitude with respect to the M-point could be observed in real time on the computer monitor. When the contraction amplitude was suppressed by 20% (using the normal amplitude as M, the change of contraction amplitude relative to the M point could be observed in real time on the computer monitor. mg/kg body weight (0.01% Neo, 0.1 ml/100 g body weight). (Note that Comment is added at the time of administration)

8. Administration 2: After recovery of muscle contraction, intraperitoneal injection of Succinylcholine 1.2 to 2.4 mg /kg body weight (0.03% Suc, 0.4 to 0.8 ml/100 g body weight), and when the contraction amplitude has been suppressed by 20%, Neo0.1 mg/kg (0.03% Suc, 0.4 to 0.8 ml/100 g body weight) is injected homogenously into the tongue vein immediately. /kg body weight (0.01% Neo, 0.1 ml/100 g body weight).

9. The recorded tibialis anterior muscle contraction graphs were analyzed and the results were discussed.

For more product details, please visit Aladdin Scientific website.

https://www.aladdinsci.com/