Delayed effects of pyridostigmine and exercise training on acetylcholinesterase and muscle tension in mouse lower extremity

Abstract

In this study, the interactive effects of pyridostigmine, a pretreatment drug against nerve agents, and exercise training on muscle tension were investigated in the mouse lower extremity anterior muscular compartment by dorsiflexion of the foot with stimulation of the peroneal nerve. Acetylcholinesterase (AChE), lipid peroxidation (in terms of the end-product malondialdehyde, MDA) and creatine phosphokinase (CPK) activity in the muscle were correlated with muscle tension. Male NIH Swiss mice were divided into four groups and treated as follows: (1) sedentary control; (2) pyridostigmine (1.2 mg/kg orally) daily for the 5th and 6th weeks; (3) exercise training for 10 weeks; and (4) pyridostigmine plus exercise training for 10 weeks. Experiments on muscle tension were conducted 4 weeks after the last dose of pyridostigmine or saline and 24 h after exercise. The muscle tension was measured in right and left legs using a tension transduction device connected to a polygraph. After muscle tension recording, mice were killed, blood and triceps muscle were isolated, and plasma CPK and muscle AChE activities, and MDA were determined. There was a significant increase in the muscle tension (P<0.05) in the group treated with pyridostigmine plus exercise as compared to the control and exercise groups. The pyridostigmine plus exercise group also showed a significant reduction in AChE activity (P<0.01) and enhanced MDA (P<0.05) in the triceps muscle. These results suggest that subchronic dosages of pyridostigmine and interaction with exercise training result in the delayed effects of reduction in muscle AChE activity and enhanced muscle tension.

Pyridostigmine Improves the Effects of Resistance Exercise Training after Myocardial Infarction in Rats

“…Other studies have corroborated these findings and have shown improved MLT in animal models of CVDs (i.e., hypertension and MI) after RT programs (Grans et al, 2014 ; Neves et al, 2016 ). Regarding PYR treatment, as expected, acetylcholinesterase activity was reduced in Inf+P when compared to non-treated groups, which paves the way to a large ACh concentration in the neuromuscular junction, possibly contributing to a better environment to improve MLT (Verma-Ahuja et al, 2000 ). However, the finding of our study does not lend support to that hypothesis, because the PYR treatment alone (Inf+P) did not elicit significant changes in MLT.…”

“…The effects of PYR treatment on muscle strength remain an understudied area and most research has failed to demonstrate improved physical capacity PYR-treated patients with and without muscle disorders submitted to PYR treatment (Breyer-Pfaff et al, 1990 ; Glikson et al, 1991 ). However, some studies have found that lower doses of PYR (1.2 mg/kg) may lead to an increase in the neuromuscular capacity of healthy mice (Verma-Ahuja et al, 2000 ). Therefore, as Inf+RT+P showed higher MLT values when compared to the other groups, we may hypothesize that PYR effects on muscle strength are dependent on a physical component.…”

PPARδ Is Required for Exercise to Attenuate Endoplasmic Reticulum Stress and Endothelial Dysfunction in Diabetic Mice

“…The exercise speed was initially set at 5 m/min for 30 min and then incrementally increased to the target speed at 8 m/min for 30 min (240 m total). This exercise intensity was well below the tolerance level of the mouse (26). Mice were exercised daily, 6 days/week, for 4 weeks after 1 week of training (5 weeks total).…”

Clinical Considerations in the Use of Pyridostigmine Bromide as Pretreatment for Nerve-Agent Exposure

“…Five recent published laboratory studies in 2000 focused on the effects of PB in combination with stress (Grauer et al 2000;Sinton et al 2000;Servatious et al 2000;Somani et al 2000;and Verma-Ahuja et al 2000). Stress alone has been shown to induce significant changes in blood-brain barrier permeability in young rats and mice, but little or no change in adult rodents.…”