Related Experiment Video
Updated: Jun 17, 2026

Application of Consistent Massage-Like Perturbations on Mouse Calves and Monitoring the Resulting Intramuscular Pressure Changes
Published on: September 20, 2019
Continuous administration of pyridostigmine improves immobilization-induced neuromuscular weakness
Christiane G Frick1, Marc Helming, J A Jeevendra Martyn
1Klinik für Anaesthesiologie, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
Objective:
To investigate the effects of continuous pyridostigmine infusion on immobilization-induced muscle weakness. Critical illness often results in immobilization of limb and respiratory muscles, leading to muscle atrophy and up-regulation of nicotinic acetylcholine receptors. Pyridostigmine reversibly blocks acetylcholinesterase and has the potential to improve neuromuscular transmission and decrease acetylcholine receptor number.
Design:
Prospective, randomized, controlled experimental study.
Setting:
Animal laboratory, university hospital.
Subjects:
Male Sprague-Dawley rats.
Interventions:
A total of 40 rats were immobilized in one hind limb by pinning knee and ankle joints. Rats received either continuous pyridostigmine (15 mg.kg.day) or saline subcutaneously via implanted osmotic pumps.
Measurements And Main Results:
After 7 days and 14 days of immobilization, neuromuscular function, atracurium pharmacodynamics, and expression of acetylcholine receptors were evaluated. At 7 days and 14 days after immobilization, muscle force decreased in all untreated groups, whereas effective doses for paralysis with atracurium and acetylcholine receptor number in the tibialis were significantly increased. Pyridostigmine-treated rats showed a significantly improved muscle force and muscle mass in the immobilized limb. This was associated with an attenuation of acetylcholine receptor up-regulation in the respective leg. At this time, the dose-response curve for atracurium on the immobilized side was shifted to the left in the pyridostigmine group. After 14 days, muscle tension was still less depressed with pyridostigmine infusion, and resistance to the effects of atracurium was still attenuated. However, there were no differences in acetylcholine receptor expression between the immobilized sides of both groups.
Conclusions:
Continuous pyridostigmine infusion improves muscle weakness after 7 days and 14 days of immobilization. The up-regulation of acetylcholine receptors and the concomitant resistance to atracurium is attenuated in animals treated with pyridostigmine after 7 days of immobilization.
Related Concept Videos
Myasthenia Gravis: Overview and Treatment
These antibodies interfere with the function of the nicotinic receptors in three ways: by binding to the receptor and disrupting acetylcholine binding; by causing cross-linking of receptors which leads...
Skeletal Muscle Relaxants: Adverse Effects
Unlike...
Myasthenia Gravis: Diagnostic Tests
The edrophonium test is a diagnostic tool for myasthenia gravis. It involves...
Skeletal Muscle Relaxants: Therapeutic Uses
Nondepolarizing (Competitive) Neuromuscular Blockers: Pharmacological Actions
Although all competitive neuromuscular blockers are designed...
Nondepolarizing (Competitive) Neuromuscular Blockers: Mechanism of Action
Competitive antagonists prevent acetylcholine from binding to its receptor, inhibiting membrane depolarization. Without conformational changes or intrinsic...
