生物谷Bioon.com 訊 一項(xiàng)研究發(fā)現(xiàn),，鍛煉引起的肌纖維核的并入可能有助于肌纖維在不使用肌肉一段時(shí)間導(dǎo)致萎縮之后恢復(fù)尺寸,。
熱衷于鍛煉的人知道肌肉力量訓(xùn)練會(huì)導(dǎo)致肌肉尺寸的增加,，而當(dāng)訓(xùn)練停止之后又會(huì)消失,；肌纖維萎縮是由于不活動(dòng),。但是此前進(jìn)行過的鍛煉能夠幫助萎縮的肌纖維在重新鍛煉之后較快地重新恢復(fù)尺寸的機(jī)制仍然不清楚,。Kristian Gundersen及其同事對(duì)嚙齒動(dòng)物的肌肉進(jìn)行了成像實(shí)驗(yàn),，從而找到這類“肌肉記憶”的細(xì)胞基質(zhì),。
這組作者發(fā)現(xiàn)，在經(jīng)過了一段類似于力量訓(xùn)練的過量鍛煉之后，新的核在肌纖維尺寸生長之前加入到了肌纖維中,。這組作者報(bào)告說,，在超負(fù)荷訓(xùn)練停止之后，肌纖維還在相當(dāng)長的時(shí)間里保持了這些核,。此外,，這些核幫助延遲了肌肉萎縮。這組作者提出,，由于產(chǎn)生新核的能力隨著年齡增長而逐漸減少,，人們可能會(huì)從年輕的時(shí)候進(jìn)行力量鍛煉中受益。（生物谷Bioon.com）
生物谷推薦原文出處：
PNAS doi: 10.1073/pnas.0913935107
Myonuclei acquired by overload exercise precede hypertrophy and are not lost upon detraining
J. C. Bruusgaard, I. B. Johansen, I. M. Egner, Z. A. Rana, and K. Gundersen 1
Department of Molecular Biosciences, University of Oslo, 0371 Oslo, Norway
Effects of previous strength training can be long-lived, even after prolonged subsequent inactivity, and retraining is facilitated by a previous training episode. Traditionally, such “muscle memory” has been attributed to neural factors in the absence of any identified local memory mechanism in the muscle tissue. We have used in vivo imaging techniques to study live myonuclei belonging to distinct muscle fibers and observe that new myonuclei are added before any major increase in size during overload. The old and newly acquired nuclei are retained during severe atrophy caused by subsequent denervation lasting for a considerable period of the animal's lifespan. The myonuclei seem to be protected from the high apoptotic activity found in inactive muscle tissue. A hypertrophy episode leading to a lasting elevated number of myonuclei retarded disuse atrophy, and the nuclei could serve as a cell biological substrate for such memory. Because the ability to create myonuclei is impaired in the elderly, individuals may benefit from strength training at an early age, and because anabolic steroids facilitate more myonuclei, nuclear permanency may also have implications for exclusion periods after a doping offense.
