Experimental action of muscarinic drugs on the tibialis anterior muscle

Summary

To study the method of preparation of the tibialis anterior muscle in the body and to observe the characteristics of the action of different types of skeletal muscle relaxants.

Operation method

electrical stimulation

Principle

Skeletal muscle relaxants are divided into two categories: depolarizing muscarinic drugs and non-depolarizing muscarinic drugs. Depolarizing muscarinic drugs are N2 receptor agonists, and non-depolarizing muscarinic drugs are N2 receptor blocking drugs, both of which can produce neuromuscular junction blockade, but the blockade modes are different, and thus the characteristics of the action are not the same. Clinically, non-depolarizing muscarinic drugs are more commonly used. Observation of the effects of atracurium and succinylcholine on the tibialis anterior muscle of rabbits in vivo and the interaction between them will help to grasp the characteristics of the effects of the two types of drugs and their clinical use.

Materials and Instruments

Rabbit
Pentobarbital sodium solution; Atracurium; Succinylcholine
Coarse scissors; syringe; surgical instruments; tracheal intubation; arterial intubation; artificial respirator; tension transducer; BL-420 biosignal recorder; stimulating electrodes; silk thread; glass beaker

Move

1. A rabbit was taken, weighed, anesthetized with 3% pentobarbital sodium solution 30 mg/kg intravenously, fixed on the rabbit table in supine position, and the rabbit's hair on the outside of the knee of the neck and one lower limb was cut off. The skin of the neck was incised in the center, the trachea was separated, a tracheal cannula was inserted, and the cannula was connected to an artificial respirator to regulate the respiratory rate of 30 breaths per minute and the tidal volume of 24~26 ml.

2. Make a longitudinal incision of about 4 cm along the skin of one side of the tibia, and expose the transverse ankle ligament below. Separate the tibialis anterior muscle, cut the transverse ligament, thread a long wire to ligate the tendon, and cut the tendon at the distal end of the ligation to free the tibialis anterior muscle. Then make a longitudinal incision in the skin under the knee joint, cut the tendon membrane, separate the common peroneal nerve, and thread it for spare. The wire ligated to the anterior tibial muscle was fixed to the tension transducer connected to the BL-420 biosignal recorder, and the stimulation electrode was connected to the common peroneal nerve.

3. Electrically stimulate the common peroneal nerve with the following stimulation parameters: frequency 0.1 Hz, wave width 1 ms, time 1 s. Record the normal tibialis anterior muscle contraction curve, and then carry out the following experiments sequentially:

(1) After the contraction curve was stabilized by stimulation, 0.05% atracurium was injected intravenously at 0.3 ml/kg, and the muscle contraction amplitude was attenuated, and then stimulated again, and the contraction curve was recorded; after the muscle contraction was recovered for 10 min, atracurium was injected again at 0.3 ml/kg, and the effect was obvious, then immediately injected intravenously at 0.05% succinylcholine at 0.5 ml/kg, and the contraction curve of the anterior tibial muscle was recorded, and the effect of succinylcholine on atracurium musculoskeletal relaxation was observed. The contraction curves of the tibialis anterior muscle were recorded to observe the effect of succinylcholine on the muscarinic effect of atracurium.

(2) After the contraction curve was stabilized by stimulation, inject 0.05% succinylcholine 0.5 ml/kg intravenously, observe and record the muscle contraction curve, and then stimulate the muscle again after the contraction amplitude was attenuated to record the change of the contraction curve; after the muscle contraction was restored for 10 min, inject 0.3 ml/kg intravenously of atracurium, and then inject 0.05% succinylcholine 0.5 ml/kg intravenously for 5 min, and record the contraction curve, and observe the effect of succinylcholine on atracurium muscular relaxation. The contraction curve was recorded to observe the effect of atracurium on the muscarinic effect of succinylcholine.

4. Plot the contraction curves of tibialis anterior muscle with different drugs and record the results.

Table Comparison of the action characteristics of the two muscarinic drugs

	Atracurium	Succinylcholine
dose
latency of action
Peak time of action
Maintenance time of action

Caveat

1. Do not injure the common peroneal nerve when separating it, give electrical stimulation after exposing the nerve, if the tibialis anterior muscle contracts, that is to prove that the nerve is the common peroneal nerve.

2. Selection of stimulation intensity: start the test with weak stimulation, and the voltage at which the stimulation increases and the contraction curve no longer rises is the required strong stimulation voltage.

3. When the effect of the drug is not obvious, additional doses can be given, and at the same time, the respiration of the animals can be carefully observed to avoid death due to individual differences in the animals.

Common Problems

1. Based on the experimentally observed characteristics of the actions of atracurium and succinylcholine, what should be noted about the clinical use of the drug?

2. what are the manifestations of different types of muscarinic drug interactions?

For more product details, please visit Aladdin Scientific website.

https://www.aladdinsci.com/