Otsenka sokratitel'noy funktsii diafragmal'noy myshtsy mSOD1 transgennykh myshey s model'yu bokovogo amiotroficheskogo skleroza

Amyotrophic lateral sclerosis (ALS) - incurable neurodegenerative disease, which is characterized by progressive loss of motoneurons, atrophy and paralysis of skeletal muscles. The main immediate cause of death in ALS patients is a paralysis of the respiratory muscles. In the present study we investigated the contractile characteristics of diaphragm muscle of mSOD1 transgenic mice with ALS model at presymptomatic (3-4 MO) and symptomatic (6-7 MO) stages of the disease. In myographic experiments under electrical stimulation of muscle we showed an increase in force and duration of a single muscle contraction, force of summed muscle contractions (5-50 Hz), diaphragmatic muscle mass at mSOD1 symptomatic mice compared to presymptomatic and wild-type mice. The absence of changes in the contraction threshold and «force-stimulus» curve at symptomatic mSOD1 mice suggests that found differences are not related to changes in the excitability of muscle fibers. Results of the study may be explained in terms of activation of compensatory mechanisms in the «motoneuron - neuromuscular synapse - skeletal muscle» in response to the development of neurodegenerative process. Presented findings extend current understanding of the pathogenesis of amyotrophic lateral sclerosis and can be used to estimate the rate of progression of the disease in mSOD transgenic animals.

amyotrophic lateral sclerosis, mSOD1 transgenic mice, diaphragm, single muscle contraction, tetanic contraction