Tag Archives: muscle contraction
The effect of chlorpyrifos upon ATPase activity of sarcoplasmic reticulum and biomechanics of skeletal muscle contraction
D. M. Nozdrenko, M. S. Miroshnychenko, V. M. Soroсa,
L. V. Korchinska, D. O. Zavodovskiy
Educational and Scientific Centre Institute of Biology,
Taras Shevchenko National University of Kyiv, Ukraine;
e-mail: ddd@univ.kiev.ua
We investigated the effect of chlorpyrifos, an organophosphate insecticide, on Ca2+,Mg2+-ATPase activity of sarcoplasmic reticulum and on contraction dynamics (force and length changes) of Rana temporaria m. tibialis anterior muscle fiber bundles. All of the used concentrations of chlorpyrifos (10-6 to 10-5 M) caused decrease of Ca2+,Mg2+-ATPase activity. The inhibition of Ca2+,Mg2+-ATPase activity by chlorpyriphos in concentrations of 10-6 M to 7.5·10-6 M is due to permeation of sarcoplasmic reticulum rather than due to direct enzyme inhibition by organophosphate insecticides. The inhibitory properties of the compound were higher at increased concentration and exposure timeframes. Chlorpyrifos in concentration range of 10-6 to 7.5·10-6 M causes changes in muscle fiber response force that were more pronounced than changes in contractile length. We demonstrated inhibition of Ca2+,Mg2+-ATPase activity caused by noncholinergic effects of chlorpyriphos. It is possible to conclude that influence of organophosphate insecticides happens not only in the neuromuscular transmission but also on the level of subcellular structures.
The effect of the aluminum chloride – quercetin complex on Ca(2+),Mg(2+)-ATPase activity and contraction dynamic properties of muscle tibialis anterior from Rana temporaria
D. M. Nozdrenko1, O. M. Аbramchuk2, V. M. Soroca1, N. S. Miroshnichenko1
1Educational and Scientific Centre “Institute of Biology”,
Taras Shevchenko National University of Kyiv, Ukraine;
2Lesya Ukrainka Eastern European National University, Lutsk, Ukraine;
e-mail: ddd@univ.kiev.ua
Combined effect of aluminum chloride and quercetin solutions on the enzymatic activity and contraction dynamics of muscle fiber bundles of the Rana temporaria m. tibialis anterior was investigated. It was shown that these complexes inhibit muscle contraction. Linear reduction of Ca2+,Mg2+-ATPase activity induced by all of the used concentrations of AlCl3 – quercetin was demonstrated. It was found that complex of quercetin with AlCl3 has a greater inhibitory effect on muscle contraction dynamic and causes greater reduction during all periods of stimulation in comparison to the separate effect of the investigated compounds. All the studied concentrations of AlCl3 and quercetin solutions (AlCl3: 10-4-10-2 M; quercetin: 10-6-10-5 M) caused concentration depended contraction strengths and lengths reduction. The decrease in strength and length of muscle contractions was of constant and mostly linear nature within observed timeframe as well as within each periods of contraction. The changes were least pronounced within pretetanic period, but were profound within terminal period of muscle activity. The changes in dynamic contraction properties and Ca2+,Mg2+-ATPase activity of sarcoplasmic reticulum under effect of the investigated compounds was minimal in the beginning of the muscle’s response to stimulus, prior to muscle strength reaching stable contraction level.
Aluminum chloride effect on Ca(2+),Mg(2+)-ATPase activity and dynamic parameters of skeletal muscle contraction
D. M. Nozdrenko1, O. M. Abramchuk2, V. M. Soroca1, N. S. Miroshnichenko1
1Taras Shevchenko National University of Kyiv, Institute of Biology, Ukraine;
2Lesya Ukrainka Eastern European National University, Lutsk, Ukraine;
e-mail: ddd@univ.kiev.ua
We studied enzymatic activity and measured strain-gauge contraction properties of the frog Rana temporaria m. tibialis anterior muscle fascicles during the action of aluminum chloride solution. It was shown that AlCl3 solutions did not affect the dynamic properties of skeletal muscle preparation in concentrations less than 10-4 M. Increasing the concentration of AlCl3 to 10-2 M induce complete inhibition of muscle contraction. A linear correlation between decrease in Ca2+,Mg2+-ATPase activity of sarcoplasmic reticulum and the investigated concentrations range of aluminum chloride was observed. The reduction in the dynamic contraction performance and the decrease Ca2+,Mg2+-ATPase activity of the sarcoplasmic reticulum under the effect of the investigated AlCl3 solution were minimal in pre-tetanus period of contraction.