The role of L-type calcium channels in the accumulation of Ca2+ in soleus muscle fibers in the rat and changes in the ratio of myosin and serca isoforms in conditions of gravitational unloading
| Autor: | Mukhina Am, T. L. Nemirovskaya, Boris Shenkman, E. G. Altaeva |
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| Rok vydání: | 2008 |
| Předmět: |
Male
Myosin Light Chains SERCA Calcium Channels L-Type Blotting Western Muscle Fibers Skeletal chemistry.chemical_element Myosins Calcium Calcium in biology Sarcoplasmic Reticulum Calcium-Transporting ATPases Isomerism Myosin Animals L-type calcium channel Rats Wistar Muscle Skeletal Soleus muscle Calcium metabolism Myosin Heavy Chains NFATC Transcription Factors Voltage-dependent calcium channel Tissue Extracts Weightlessness Chemistry musculoskeletal neural and ocular physiology General Neuroscience Calcium Channel Blockers musculoskeletal system Immunohistochemistry Rats Biochemistry Biophysics |
| Zdroj: | Neuroscience and Behavioral Physiology. 38:181-188 |
| ISSN: | 1573-899X 0097-0549 |
| Popis: | Gravitational unloading is known to produce changes in the expression of a number of contractile and regulatory proteins in the soleus muscle. This applies particularly to isoforms of myosin heavy chains (MHC) and SERCA sarcoplasmic reticulum calcium pumps. Unloading increases the resting levels of extracellular calcium in soleus muscle fibers. The present study addresses verification of the hypothesis that changes in the expression of MHC and SERCA isoforms in gravitational unloading are linked with the accumulation of calcium ions in the myoplasm of muscle fibers. It is suggested that specific blockade of L-type calcium channels using nifedipine decreases the myoplasmic calcium ion concentration, thus preventing the development of changes in the expression of MHC and SERCA isoforms. A total of 36 male Wistar rats were divided into three groups: a control group, an unloading group using the Morley-Holton soleus muscle functional unloading model, and an unloading + nifedipine group, where animals received daily nifedipine (7 mg/kg/day) with their drinking water on the background of suspension. The results showed that blockade of L-type calcium channels on the background of gravitational unloading significantly decreased the extent of calcium ion accumulation in the myoplasm of soleus muscle fibers, which partly prevented the transformation of muscle fibers (in relation to the fast and slow isoforms of MHC and SERCA) to the rapid type. There was no nuclear translocation of the greater part of transcription factor NFATc1, as seen on unloading. |
| Databáze: | OpenAIRE |
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