Muscle composition after 14-day hindlimb unloading in rats: effects of two herbal compounds.

Abstract

AIM:

We studied the potential of two herbal compounds (HC-1 and HC-2) in different dosages (HC-1, containing ligustrazine; HC-2, containing radix astragali) as a countermeasure against muscle atrophy in a hindlimb unloading rat model. Soleus muscle weight, fiber type distribution, cross-sectional area (CSA), and myosin ATPase activity were measured.

METHODS:

Six rats each were assigned to a nine-group design: Control (CON); hindlimb unloading only (HLU); hindlimb unloading plus intragastric water instillation (HLU-W); and hindlimb unloading plus different dosages of instilled HC-1 (HLU-HC-1l, HLU-HC-1m, HLU-HC-1h) or HC-2 (HLU-HC-2l, HLU-HC-2m, HLU-HC-2h).

RESULTS:

As expected, in HLU and HLU-W, soleus muscle-to-body weight ratio and CSA of type I and II fiber went down, and myosin ATPase activity and the percentage of type II fibers went up, all compared with CON. Compared to untreated rats, high-dose HC-1 enhanced type I and II fiber CSA by 77% and 55%, respectively; myosin ATPase activity (type II fiber percentage) were lower, but soleus muscle-to-body weight ratio did not change. High-dose HC-2 enhanced soleus muscle-to-body weight ratio by 33%; and type I / type II fiber CSA by 143% and 83% above HLU-W values, respectively, and resulted in a slower myosin ATPase activity (corresponding to a lower type II fiber percentage). Low- to mid-dose HC-1 and HC-2 showed some preventive effects as well.

CONCLUSION:

HC-1 and HC-2 in proper dosages diminished muscle atrophy that otherwise occurs in simulated weightlessness.

• Authors: Haixiang Zhang, Zhixian He, Yunfang Gao, Helmut G Hinghofer-Szalkay, Xiaoli Fan
• Journal: Aviation, space, and environmental medicine (Aviat Space Environ Med) Vol. 78 Issue 10 Pg. 926-31 (Oct 2007) ISSN: 0095-6562 [Print] United States
• PMID: 17955939 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Drugs, Chinese Herbal
• Pyrazines
• Huang Qi
• Myosins
• tetramethylpyrazine

Topics

• Analysis of Variance
• Animals
• Astragalus propinquus
• Drugs, Chinese Herbal (pharmacology)
• Female
• Hindlimb Suspension
• Muscle, Skeletal (drug effects)
• Muscular Atrophy (prevention & control)
• Myosins (analysis)
• Pyrazines (pharmacology)
• Random Allocation
• Rats
• Rats, Sprague-Dawley
• Weightlessness Simulation