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Journal of Zhejiang University SCIENCE B 2007 Vol.8 No.12 P.867~874

http://doi.org/10.1631/jzus.2007.B0867


A new linearly-combined bi-exponential model for kinetic analysis of the isometric relaxation process of Bufo gastrocnemius under electric stimulation in vitro


Author(s):  Guo Rui, Li Sheng-bing, Zhao Li-na, Zhao Yun-sheng, Lu Wei, Yuan Pei, Deng Ping, Liao Fei

Affiliation(s):  Unit of Biochemical Pharmacology and Protein Biotechnology, Chongqing Key Laboratory of Biochemistry and Molecular Pharmacology, College of Pharmaceutical Sciences, Chongqing Medical University, Chongqing 400016, China

Corresponding email(s):   liaofeish@yahoo.com, liaofeish@vip.sina.com

Key Words:  Bufo gastrocnemius, Ca2+-pump, Cyclopiazonic acid (CPA), Linearly-combined bi-exponential model, Muscle relaxation rate, Residual distribution, Rest tension


Guo Rui, Li Sheng-bing, Zhao Li-na, Zhao Yun-sheng, Lu Wei, Yuan Pei, Deng Ping, Liao Fei. A new linearly-combined bi-exponential model for kinetic analysis of the isometric relaxation process of Bufo gastrocnemius under electric stimulation in vitro[J]. Journal of Zhejiang University Science B, 2007, 8(12): 867~874.

@article{title="A new linearly-combined bi-exponential model for kinetic analysis of the isometric relaxation process of Bufo gastrocnemius under electric stimulation in vitro",
author="Guo Rui, Li Sheng-bing, Zhao Li-na, Zhao Yun-sheng, Lu Wei, Yuan Pei, Deng Ping, Liao Fei",
journal="Journal of Zhejiang University Science B",
volume="8",
number="12",
pages="867~874",
year="2007",
publisher="Zhejiang University Press & Springer",
doi="10.1631/jzus.2007.B0867"
}

%0 Journal Article
%T A new linearly-combined bi-exponential model for kinetic analysis of the isometric relaxation process of Bufo gastrocnemius under electric stimulation in vitro
%A Guo Rui
%A Li Sheng-bing
%A Zhao Li-na
%A Zhao Yun-sheng
%A Lu Wei
%A Yuan Pei
%A Deng Ping
%A Liao Fei
%J Journal of Zhejiang University SCIENCE B
%V 8
%N 12
%P 867~874
%@ 1673-1581
%D 2007
%I Zhejiang University Press & Springer
%DOI 10.1631/jzus.2007.B0867

TY - JOUR
T1 - A new linearly-combined bi-exponential model for kinetic analysis of the isometric relaxation process of Bufo gastrocnemius under electric stimulation in vitro
A1 - Guo Rui
A1 - Li Sheng-bing
A1 - Zhao Li-na
A1 - Zhao Yun-sheng
A1 - Lu Wei
A1 - Yuan Pei
A1 - Deng Ping
A1 - Liao Fei
J0 - Journal of Zhejiang University Science B
VL - 8
IS - 12
SP - 867
EP - 874
%@ 1673-1581
Y1 - 2007
PB - Zhejiang University Press & Springer
ER -
DOI - 10.1631/jzus.2007.B0867


Abstract: 
There was a slow-relaxing tail of skeletal muscles in vitro upon the inhibition of ca2+-pump by cyclopiazonic acid (CPA). Herein, a new linearly-combined bi-exponential model to resolve this slow-relaxing tail from the fast-relaxing phase was investigated for kinetic analysis of the isometric relaxation process of Bufo gastrocnemius in vitro, in comparison to the single exponential model and the classical bi-exponential model. During repetitive stimulations at a 2-s interval by square pulses of a 2-ms duration at 12 V direct currency (DC), the isometric tension of Bufo gastrocnemius was recorded at 100 Hz. The relaxation curve with tensions falling from 90% of the peak to the 15th datum before next stimulation was analyzed by three exponential models using a program in MATLAB 6.5. Both the goodness of fit and the distribution of the residuals for the best fitting supported the comparable validity of this new bi-exponential model for kinetic analysis of the relaxation process of the control muscles. After CPA treatment, however, this new bi-exponential model showed an obvious statistical superiority for kinetic analysis of the muscle relaxation process, and it gave the estimated rest tension consistent to that by experimentation, whereas both the classical bi-exponential model and the single exponential model gave biased rest tensions. Moreover, after the treatment of muscles by CPA, both the single exponential model and the classical bi-exponential model yielded lowered relaxation rates, nevertheless, this new bi-exponential model had relaxation rates of negligible changes except much higher rest tensions. These results suggest that this novel linearly-combined bi-exponential model is desirable for kinetic analysis of the relaxation process of muscles with altered ca2+-pumping activity.

Darkslateblue:Affiliate; Royal Blue:Author; Turquoise:Article

Reference

[1] Bassani, J.W., Bassani, R.A., Bers, D.M., 1994. Relaxation in rabbit and rat cardiac cells: species-dependent differences in cellular mechanisms. J. Physiol., 476(2):279-293.

[2] Baudet, S., Noireaud, J., 1999. Pharmacologic evaluation of isometric contraction-relaxation coupling indexes in rabbit ventricular muscle. J. Pharmacol. Toxicol. Methods, 42(1):21-30.

[3] Belus, A., Piroddi, N., Tesi, C., 2003. Mechanism of cross-bridge detachment in isometric force relaxation of skeletal and cardiac myofibrils. J. Muscle Res. Cell. Motil., 24(4-6):261-267.

[4] Booth, J., Mckenna, M.J., Ruell, P.A., Gwinn, T.H., Davis, G.M., Thompson, M.W., Harmer, A.R., Hunter, S.K., Sutton, J.R., 1997. Impaired calcium pump function does not slow relaxation in human skeletal muscle after prolonged exercise. J. Appl. Physiol., 83(2):511-521.

[5] Creazzo, T.L., Burch, J., Godt, R.E., 2004. Calcium buffering and excitation-contraction coupling in developing avian myocardium. Biophys. J., 86(2):966-977.

[6] Dobrunz, L.E., Backx, P.H., Yue, D.T., 1995. Steady-state [Ca2+]i-force relationship in intact twitching cardiac muscle: direct evidence for modulation by isoproterenol and EMD 53998. Biophys. J., 69(1):189-201.

[7] Laporte, R., Hui, A., Laher, I., 2004. Pharmacological modulation of sarcoplasmic reticulum function in smooth muscle. Pharmacol. Rev., 56(4):439-513.

[8] Liao, F., Zheng, R.L., Gao, J.J., Jia, Z.J., 1999. Retardation of skeletal muscle fatigue by the two phenylpropanoid glycosides: verbascoside and martynoside from Pedicularis plicata Maxim. Phytother. Res., 13(7):621-623.

[9] Liao, F., Guo, R., Li, S.B., Zuo, Y.P., Lu, J., Sun, A.P., 2008. Characterizing isometric contractility of Bufo gastrocnemius in vitro by rest tension. J. South Med. Univ., in press (in Chinese).

[10] Matsubara, H., Takaki, M., Yasuhara, S., Araki, J., Suga, H., 1995. Logistic time constant of isovolumic relaxation pressure-time curve in the canine left ventricle: better alternative to exponential time constant. Circulation, 92(8):2318-2326.

[11] Même, W., Huchet-Cadiou, C., Léoty, C., 1998. Cyclopiazonic acid-induced changes in the contraction and Ca2+ transient of frog fast-twitch skeletal muscle. Am. J. Physiol., 274(1):C253-C261.

[12] Mizuno, J., Araki, J., Mikane, T., Mohri, S., Imaoka, T., Matsubara, H., Okuyama, H., Kurihara, S., Ohe, T., Hirakawa, M., Suga, H., 2000. Logistic time constant of isometric relaxation force curve of ferret ventricular papillary muscle: reliable index of lusitropism. Jpn. J. Physiol., 50(5):479-487.

[13] Mizuno, J., Mohri, S., Shimizu, J., Suzuki, S., Mikane, T., Araki, J., Matsubara, H., Morita, T., Hanaoka, K., Suga, H., 2006. Starling-effect-independent lusitropism index in canine left ventricle: logistic time constant. Anesth. Analg., 102(4):1032-1039.

[14] Mizuno, J., Otsuji, M., Takeda, K., Yamada, Y., Arita, H., Hanaoka, K., Hirano, S., Kusakari, Y., Kurihara, S., 2007. Superior logistic model for decay of Ca2+ transient and isometric relaxation force curve in rabbit and mouse papillary muscles. Int. Heart J., 48(2):215-232.

[15] Morgan, D.L., Claflin, D.R., Julian, F.J., 1997. The relationship between tension and slowly varying intracellular calcium concentration in intact frog skeletal muscle. J. Physiol., 500(1):177-192.

[16] Mutungi, G., Ranatunga, K.W., 2000. Sarcomere length changes during end-held (isometric) contractions in intact mammalian (rat) fast and slow muscle fibres. J. Muscle Res. Cell Motil., 21(6):565-575.

[17] Plenge-Tellechea, F., Soler, F., Fernandez-Belda, F., 1997. On the inhibition mechanism of sarcoplasmic or endoplasmic reticulum Ca2+-ATPases by cyclopiazonic acid. J. Biol. Chem., 272(5):2794-2800.

[18] Poggesi, C., Tesi, C., Stehle, R., 2005. Sarcomeric determinants of striated muscle relaxation kinetics. Pflugers Arch., 449(6):505-517.

[19] Seidler, N.W., Jona, I., Vegh, M., Martonosi, A., 1989. Cyclopiazonic acid is a specific inhibitor of the Ca2+-ATPase of sarcoplasmic reticulum. J. Biol. Chem., 264(30):17816-17823.

[20] Tamiya, K., Beppu, T., Ishihara, K., 1995. Double-exponential curve fitting of isometric relaxation: a new measure for myocardial lusitropism. Am. J. Physiol., 269(2): H393-H406.

[21] Tesi, C., Piroddi, N., Colomo, F., Poggesi, C., 2002. Relaxation kinetics following sudden Ca(2+) reduction in single myofibrils from skeletal muscle. Biophys. J., 83(4):2142-2151.

[22] Westerblad, H., Lännergren, J., Allen, D.G., 1997. Slowed relaxation in fatigued skeletal muscle fibers of Xenopus and mouse. Contribution of [Ca2+]i and cross-bridges. J. Gen. Physiol., 109(3):385-399.

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