• KSBB Journal
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• 제26권3호
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• pp.211-216
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• 2011

To study the effects of ethanol extract of the Rhodiola Sachalinensis on the anti-oxidation and blood pressure and skeletal muscles contractility in rats. The ethanol extracts and fractions of Rhodiola Sachalinensis were determinated the anti-oxidation effects by DPPH(1,1-dipenyl-2-picrylhydrazyl) method and comparing with the BHA (Butylated hydroxyanisole) and AA(Ascorbic acid). The gastrocnemius and soleus muscle contractility were observed by stimulating the sciatic nerve with electricity after affusing stomach with ethanol extract of the 200 mg/kg dosage of Rhodiola Sachalinensis for 4 weeks. The ethanol extract of the Rhodiola Sachalinensis could shorten latent period, increase maximal contractive extent and time and relaxative time at the twitch and complete tetanus of gastrocnemius and soleus muscles. The ethanol extract of the Rhodiola Sachalinensis shows high anti-oxidation effect and can enhance skeletal muscles contractility in rats.

• The Journal of Korean Physical Therapy
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• 제19권4호
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• pp.1-14
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• 2007

Background: It is generally accepted that skeletal muscle contraction is triggered by nerve impulse and intracellular $Ca^{2+}\;([Ca^{2+}]_i)$ released from intracellular $Ca^{2+}$ stores such as sarcoplasmic reticulum (SR). Specifically, this process, called excitation-contraction (E-C) coupling, takes place at intracellular junctions between the plasma membrane, the transverse (T) tubule L-type $Ca^{2+}$ channel (dihydropyridine-sensitive L-rype $Ca^{2+}$ channel, DHPR, also called tetrads), and the SR $Ca^{2+}$ release channel (ryanodine-sensitive $Ca^{2+}$ release channel, RyR, also called feet) of internal $Ca^{2+}$ stores in skeletal muscle cells. Furthermore, it has been reported that the $Ca^{2+-}$ dependent and -independent contraction determine the expression of skeletal muscle genes, thus providing a mechanism for tightly coupling the extent of muscle contraction to regulation of muscle plasticity-related excitation-transcription (E-T) coupling. Purpose: Expression and activity of plasticity-associated enzymes in gastrocnemius muscle strips have not been well studied, however. Methods: Therefore, in this study the expression and phosphorylation of E-C and E-T coupling-related mediators such as protein kinases, ROS(reactive oxygen species)- and apoptosis-related substances, and others in gastrocnemius muscles from rats was examined. Results: I found that expression and activity of MAPKs (mitogen-activated protein kinases, ERK1/2, p38MAPK, and SAPK/JNK), apoptotic proteins (cleaved caspase-3, cytochrome c, Ref-1, Bad), small GTP-binding proteins (RhoA and Cdc42), actin-binding protein (cofilin), PKC (protein kinase C) and $Ca^{2+}$ channel (transient receptor potential channel 6, TRPC6) was observed in rat gastrocnemius muscle strips. Conclusion: These results suggest that MAPKs, ROS- and apoptosis-related enzymes, cytoskeleton-regulated proteins, and $Ca^{2+}$ channel may in part functionally import in E-C and E-T coupling from rat skeletal muscles.

• Molecules and Cells
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• 제22권3호
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• pp.275-284
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• 2006

The molecular components that generate and maintain circadian rhythms of physiology and behavior in mammals are present both in the brain (suprachiasmatic nucleus; SCN) and in peripheral tissues. Examination of mice with targeted disruptions of either mPer1 or mPer2 has shown that these two genes have key roles in the SCN circadian clock. Here we show that loss of the clock gene mPer2 affects forced locomotor performance in mice without altering muscle contractility. A proteomic analysis revealed that the anterior tibialis muscles of the mPer2 knockout mice had higher levels of glycolytic enzymes such as triose phosphate isomerase and enolase than those of either the wild type or mPer1 knockout mice. In addition, the level of expression of HSP90 in the mPer2 mutant mice was also significantly higher than in wildtype mice. These results suggest that the reduced locomotor endurance of the mPer2 knockout mice reflects a greater dependence on anaerobic metabolism under stress conditions, and that the two canonical clock genes, mPer1 and mPer2, play distinct roles in the physiology of skeletal muscle.