BOTULINUM TOXIN-INDUCED PARALYSIS LEADS TO SLOWER MYOSIN HEAVY CHAIN ISOFORM COMPOSITION AND REDUCED TITIN CONTENT IN JUVENILE RAT GASTROCNEMIUS MUSCLE
BOTULINUM TOXIN-INDUCED PARALYSIS LEADS TO SLOWER MYOSIN HEAVY CHAIN ISOFORM COMPOSITION AND REDUCED TITIN CONTENT IN JUVENILE RAT GASTROCNEMIUS MUSCLE
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DOI：
10.1002/mus.21247
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发表时间：
2009-04-01
期刊：
影响因子：
3.4
通讯作者：
Smith, Heather K.
中科院分区：
文献类型：
--
作者：
Legerlotz, Kirsten;Matthews, Kenneth G.;Smith, Heather K.
肌肉注射肉毒杆菌毒素A（Btx-A）和运动用于治疗脑瘫儿童的肌肉痉挛。然而，人们对Btx-A诱导瘫痪后肌肉内的生物学变化以及Btx-A和运动的结合如何影响生长的肌肉知之甚少。湿质量，肌球蛋白重链（MHC）的组成，和肌联蛋白含量的幼年大鼠腓肠肌Btx-A注射后3周，随后自愿轮运行运动。Btx-A使IIa型（+121%）和IIx型（+65%）MHC比例增加，而使IIb型MHC比例降低（-51%），肌联蛋白含量降低（-18%）。运动并没有放大或减少Btx-A引起的变化。因此，我们的结论是，虽然瘫痪肌肉的肌节稳定性可能会受损，适度的机械负荷似乎并不影响瘫痪肌肉蛋白质的组成。
Intramuscular injections of botulinum toxin A (Btx-A) and exercise are used in the treatment of muscle spasticity in children with cerebral palsy. However, little is known about the biological changes within muscle subsequent to Btx-A-induced paralysis and how the combination of Btx-A and exercise might affect the growing muscle. The wet mass, myosin heavy chain (MHC) composition, and titin content of the juvenile rat gastrocnemius muscle were determined 3 weeks after Btx-A injections and subsequent voluntary wheel-running exercise. Btx-A increased the proportion of type IIa (+121%) and IIx (+65%) MHC while decreasing the proportion of type IIb MHC (-51%) and reducing the titin content (-18%). Exercise did not amplify or reduce the changes induced by Btx-A. Thus, we conclude that although the sarcomeric stability of paralyzed muscle might be impaired, moderate mechanical loading does not seem to affect paralyzed muscle protein composition.