EFFECTS OF A CHRONIC WASTING INFECTION ON SKELETAL-MUSCLE SIZE AND CONTRACTILE PROPERTIES
EFFECTS OF A CHRONIC WASTING INFECTION ON SKELETAL-MUSCLE SIZE AND CONTRACTILE PROPERTIES
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DOI：
10.1152/jappl.1988.64.1.460
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发表时间：
1988-01-01
影响因子：
3.3
通讯作者：
ROCHESTER, DF
中科院分区：
文献类型：
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作者：
DREW, JS;FARKAS, GA;ROCHESTER, DF
为了评估慢性感染对骨骼肌大小和收缩特性的影响，我们使用了内脏利什曼病的仓鼠模型，内脏利什曼病是一种由杜氏利什曼原虫(LD)引起的网状内皮系统的寄生性感染。为了区分减少卡路里摄入量和感染本身的影响，我们还研究了健康对照动物和受到热量限制的非感染动物。在体外测试了三块肌肉：足底肌、比目鱼肌和横隔肌。卡路里限制和LD感染都导致体重减轻，肌肉横截面积和湿重减少。这些干预措施对体外收缩特性有不同的影响，最显著的是降低了对强直性刺激的峰值张力。除LD感染动物的足底张力损失65%外，其余均为35-45%。我们得出结论，慢性LD感染对骨骼肌有间接和直接的影响。1)厌食症导致的卡路里摄入量减少会减少肌肉大小和主动张力。停用可能会增强四肢肌肉的这种效果。2)感染以未知的机制引起迟钝的快速抽动肌的严重无力。
To evaluate the effects of chronic infection on skeletal muscle dimensions and contractile properties, we used a hamster model of visceral leishmaniasis, a parasitic infection of the reticuloendothelial system produced by Leishmania donovani (LD). To distinguish between effects of reduced caloric intake and infection per se, we also studied healthy control animals and noninfected animals subjected to caloric restriction. Three muscles were tested in vitro: plantaris, soleus, and diaphragm. Both caloric restriction and LD infection caused loss of body weight and reduced muscle cross-sectional areas and wet weights. The interventions had variable effects on in vitro contractile properties, the most pronounced being reduction in peak tension in response to tetanic stimulation. Tension loss was 35-45%, except for a loss of 65% in plantaris of LD-infected animals. We conclude that chronic LD infection affects skeletal muscles in both indirect and direct ways. 1) Reduced caloric intake due to anorexia decreases muscle size and active tension. Disuse probably enhances this effect in limb muscles. 2) Infection produces profound weakness of inactive fast-twitch muscle by unknown mechanisms.