Therefore, in this study gastrocnemius muscle tension was measured before and after injection; then these measurements were used to calculate reduction rates. By controlling for the individual differences in muscle capacity in each rat, muscle cramp reduction rates were able to be compared via groups, and significant outcomes were obtained. This is consistent with the results of a previous study investigating the extraction efficiency of Jakyak-Gamcho decoctions [ 17 ].
Particularly, among the constituents of Jakyak-Gamcho decoction, Radix Glycyrrhizae has significant spasmolytic activity [ 9 ]. In this current study, the yields of the Radix Glycyrrhizae constituents glycyrrhizin and isoliquiritin were 1. This confirmed that different extractants can yield different amounts of active components related to the spasmolytic effects of Jakyak-Gamcho decoctions.
In herbal medicines, intracellular contents from which active components are derived are extracted through cell walls or by breaking down cell walls [ 19 , 20 ]. In the case of ethanol extraction in herbal medicine, ethanol solvents break down the cell walls of medicinal ingredients, facilitating the extraction of active components from within the cells [ 21 , 22 ].
We suggest that this is because ethanol breaks down the cell walls of the ingredients of oriental medicines, ultimately enhancing extraction efficiency. Since ethanol can explode when heated, a traditional boiling method was not used in the extraction of Jakyak-Gamcho decoction with ethanol in this study. Instead, ultrasound-reflux extraction, which is known to be effective for herbal medicines [ 19 , 20 ], was used.
To ensure an accurate comparison between the two solvents investigated, the same ultrasound-reflux extraction method was used for the water-extracted Jakyak-Gamcho decoction. Several studies have investigated the threshold frequency at which complete tetanus starts to develop and continue [ 23 — 25 ].
However, the threshold frequency at which complete tetanus reportedly started in these previous studies differed from the initiating frequency observed in this current study [ 9 ].
This is likely due to differences in experimental conditions and inconsistent operational definitions of complete tetanus. As muscle cramping is an instant musculoskeletal condition and is accompanied by instant intense pain, we designed an electrical stimulation experiment that can induce maximum muscle contraction instantly in spite of its short duration.
This might have been because glycyrrhetinic acid, which is glycyrrhizin's hydrolysis product, had not yet been absorbed sufficiently to yield an effect. Glycyrrhetinic acid is a major component for spasmolytic effect [ 9 ]. It has been reported that the highest plasma concentration of glycyrrhetinic acid is observed 8—10 hours after oral administration [ 26 ].
Although intraduodenal administration can increase the rate of absorption, 1 hour might not be enough to yield a spasmolytic effect. However, further studies are needed to elucidate the pharmacological mechanism of Jakyak-Gamcho decoction, which makes it effective as a spasmolytic agent in case of pathological muscle cramps but not for physiological muscle contraction. Even at an equivalent dose 0.
Only when 0. Limitations of this study include that an electrical stimulation differs from general muscle cramp causes.
Electrical stimulation-induced muscle cramps may possess different physiological characteristics to general muscle cramps. In addition, the surgery was invasive, which may have led to additional differences between the physiological conditions in the study and those of naturally occurring muscle cramps. However, direct muscle tension measurement is required in order to measure muscle cramps, so invasive surgery procedures were unavoidable. In the present study, we increased the efficiency of Jakyak-Gamcho extraction by using an alternative extractant to water and confirmed that this corresponded with an increase in the spasmolytic effectiveness of Jakyak-Gamcho decoction in an animal model.
To date, Jakyak-Gamcho decoctions have been shown to be effective for muscle relaxation and muscle pain alleviation [ 9 , 12 — 14 , 29 ].
In this current in vivo study, ethanol-extracted Jakyak-Gamcho decoction was superior to water-extracted Jakyak-Gamcho decoction with regard to both extraction efficiency and spasmolytic effects. The elucidation of changes in the dosages of herbal medicines in the form of powders is required, for the quantitative standardization of their active components. The results of this current study suggest changes in extraction methods when Jakyak-Gamcho decoctions are prepared and converted into powder form.
Moreover, the results suggest that it may be worthwhile to investigate alternative extraction methods in terms of extraction efficiency and in vivo effectiveness for other herbal medicines besides Jakyak-Gamcho decoction. This study confirmed that differences in the amounts of effective index components in Jakyak-Gamcho decoctions resulted in differences in their effects in vivo. The results of this study suggest that it may be worthwhile to investigate alternative extraction methods in terms of extraction efficiency and in vivo effectiveness for other herbal medicines in the future.
The authors declare no conflict of interests, and all authors have approved the final paper. National Center for Biotechnology Information , U.
Evid Based Complement Alternat Med. Published online Oct Author information Article notes Copyright and License information Disclaimer. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This article has been cited by other articles in PMC.
Abstract Aim. Introduction Oriental medicine treatment modalities including acupuncture, moxibustion, and herbal medicines are effective for the treatment of musculoskeletal conditions [ 1 — 5 ]. Materials and Methods 2.
Experimental Animals Four male Wistar rats aged weeks and weighing High-Performance Liquid Chromatography Analysis The Jakyak-Gamcho decoctions derived via different solvents were subjected to high-performance liquid chromatography HPLC analysis to investigate differences in the levels of effective index components. Table 1 Gradient details. Open in a separate window. Electrical Stimulation Experiment 2.
Surgery After inducing inhalation anesthesia with isoflurane, 1. Figure 1. Electrical Stimulation and Muscle Cramp Induction Only complete tetanus was deemed to constitute muscle cramping, and incomplete tetanus was deemed to constitute physiological muscle contraction. Statistical Analysis Based on tension measurements before and after medicine injection, muscle cramp reduction rates were calculated and used in analyses.
Results 3. Figure 2. In this case, individual muscle contractions completely fuse to produce one large muscle contraction. Also Know, what is the difference between a muscle twitch and tetanus? Twitch summation or treppe is the addition of a second twitch , resulting in greater tension, and it results from stimulating the muscle before it has a chance to relax completely.
Tetanus is prolonged contraction without relaxation and results from repeating stimulation before the muscle has a chance to relax at all. What is the difference between incomplete tetanus and complete tetanus?
Incomplete tetanus has a relaxation period during contractions and Complete tetanus has no relaxation period during contractions. What is lactic acid? Summation occurs as successive stimuli are added together to produce a stronger muscle contraction. Tetanus is the fusion of contractions to produce a continuous contraction. Increasing the number of motor neurons involved increases the amount of motor units activated in a muscle, which is called recruitment.
Cardiac muscle is a unique tissue forming the wall of the heart. The properties of cardiac muscle cell membranes differ from those of skeletal muscle fibres. As a result, cardiac muscle tissue cannot undergo tetanus sustained contraction.
This property is important because a heart in tetany could not pump blood. Tetanus is caused by a toxin made by spores of bacteria, Clostridium tetani, found in soil, dust and animal feces. When the spores enter a deep flesh wound, they grow into bacteria that can produce a powerful toxin, tetanospasmin.
The toxin impairs the nerves that control your muscles motor neurons. The heart cannot be tetanized , or go into sustained involuntary contractions, because of the long refractory period of the muscle, during which it does not respond to stimulus.
This is the maximum possible contraction. During tetanus contractions, the muscles may remain shorter, longer, or constant. Tetanus contraction is usually normal for example, when holding a heavy box.
Tetanus was observed at pacing intervals of 20 ms. Tetanus often begins with mild cramps in the jaw muscles, also called jaw block or trismus. Cramps can also affect the muscles of the face, resulting in an appearance called risus sardonicus. Muscle spasms in the back often cause swelling called an opisthotonus.
A single tic has three components. The latency or delay phase, the contraction phase and the relaxation phase. Tetany can be the result of an electrolyte imbalance. There is often an extremely low level of calcium, also known as hypocalcemia. Tetany can also be caused by a magnesium or potassium deficiency. Too much acid acidosis or too much alkali alkalosis in the body can also lead to tetany.
Tetany, or tetanus crisis, is a medical sign of involuntary muscle contraction that can be caused by conditions that increase the rate of action potential of the muscle cells or nerves that innervate them. The refractory period of heart muscle is significantly longer than that of skeletal muscle.
This prevents tetanus from occurring and ensures that there is enough time after each contraction for the ventricle to fill with blood for the next contraction.
To prevent complete muscle fatigue, motor units are generally not all simultaneously active, but instead some motor units rest while others are active, which allows for longer muscle contractions.
The nervous system uses recruitment as a mechanism to efficiently utilize a skeletal muscle. When a skeletal muscle fiber contracts, myosin heads attach to actin to form cross-bridges followed by the thin filaments sliding over the thick filaments as the heads pull the actin, and this results in sarcomere shortening, creating the tension of the muscle contraction. The cross-bridges can only form where thin and thick filaments already overlap, so that the length of the sarcomere has a direct influence on the force generated when the sarcomere shortens.
This is called the length-tension relationship. Figure 2. The Ideal Length of a Sarcomere. Sarcomeres produce maximal tension when thick and thin filaments overlap between about 80 percent to percent. The ideal length of a sarcomere to produce maximal tension occurs at 80 percent to percent of its resting length, with percent being the state where the medial edges of the thin filaments are just at the most-medial myosin heads of the thick filaments Figure 2.
This length maximizes the overlap of actin-binding sites and myosin heads. If a sarcomere is stretched past this ideal length beyond percent , thick and thin filaments do not overlap sufficiently, which results in less tension produced. If a sarcomere is shortened beyond 80 percent, the zone of overlap is reduced with the thin filaments jutting beyond the last of the myosin heads and shrinks the H zone, which is normally composed of myosin tails.
Eventually, there is nowhere else for the thin filaments to go and the amount of tension is diminished. If the muscle is stretched to the point where thick and thin filaments do not overlap at all, no cross-bridges can be formed, and no tension is produced in that sarcomere.
This amount of stretching does not usually occur, as accessory proteins and connective tissue oppose extreme stretching. A single action potential from a motor neuron will produce a single contraction in the muscle fibers of its motor unit. This isolated contraction is called a twitch. A twitch can last for a few milliseconds or milliseconds, depending on the muscle type. The tension produced by a single twitch can be measured by a myogram , an instrument that measures the amount of tension produced over time Figure 3.
Each twitch undergoes three phases. Figure 3. A Myogram of a Muscle Twitch. A single muscle twitch has a latent period, a contraction phase when tension increases, and a relaxation phase when tension decreases. During the latent period, the action potential is being propagated along the sarcolemma. A series of action potentials to the muscle fibers is necessary to produce a muscle contraction that can produce work. Normal muscle contraction is more sustained, and it can be modified by input from the nervous system to produce varying amounts of force; this is called a graded muscle response.
0コメント