Infuence of 7 days of hindlimb suspension and intermittent weight support on rat muscle mechanical properties

David J Pierotti, R. R. Roy, V. Flores, V. R. Edgerton

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

Unloading the rat hindlimb results in a decrease in mass, especially in those muscles that normally have a load-bearing function. The present study was designed to evaluate the effect of intermittent periods of weight support in ameliorating this atrophic response. Adult male Sprague-Dawley rats were assigned to either a control (CON), a hindlimb suspended (HS), or a hindlimb suspended plus intermittent weight support (HS-WS) group. HS-WS rats were walked slowly on a treadmill at 0.2 m/s and a 19% incline for 10 min, every 6 h. After 7 d, the in situ mechanical properties of the soleus (Sol) and medial gastrocnemius (MG) were studied. Body weights of HS and HS-WS rats were 9 and 13% lower than CON. The Sol weight relative to body weight was 21 and 9% lower in HS and HS-WS than CON. Maximum tetanic tension relative to muscle mass was significantly lower in HS than CON, whereas HS-WS had values similar to CON. The MG weight relative to body weight was significantly lower in both suspended groups. The maximun tetanic tension relative to muscle weight was significantly lower in both suspended groups. The maximum tetanic tension relative to muscle weight was significantly elevated in HS-WS compared to CON, suggesting that weight support may have preferentially maintained the contractile protein component of the muscle. Contraction times were 25% faster (p<0.05) in the Sol and unchanged in the MG of HS rats. For each muscle, the fatigue properties were similar in all groups. These data indicate that a low-force, short-duration exercise regime results in a significant functional recovery in the 'slow' Sol, whereas the 'fast' MG is less affected. Further, these data indicate that the amount and/or intensity of exercise necessary to maintain the functional integrity of the Sol appears to be minimal.

Original languageEnglish (US)
Pages (from-to)205-210
Number of pages6
JournalAviation Space and Environmental Medicine
Volume61
Issue number3
StatePublished - 1990
Externally publishedYes

Fingerprint

Hindlimb Suspension
Hindlimb
Muscle
Rats
Weights and Measures
Muscles
Mechanical properties
Bearings (structural)
Exercise equipment
Body Weight
Unloading
Fatigue of materials
Contractile Proteins
Recovery
Self-Help Groups
Weight-Bearing
Fatigue
Sprague Dawley Rats

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health
  • Pollution
  • Medicine(all)

Cite this

Infuence of 7 days of hindlimb suspension and intermittent weight support on rat muscle mechanical properties. / Pierotti, David J; Roy, R. R.; Flores, V.; Edgerton, V. R.

In: Aviation Space and Environmental Medicine, Vol. 61, No. 3, 1990, p. 205-210.

Research output: Contribution to journalArticle

@article{16dcaf78d1e64523adfd6f24feceb3cf,
title = "Infuence of 7 days of hindlimb suspension and intermittent weight support on rat muscle mechanical properties",
abstract = "Unloading the rat hindlimb results in a decrease in mass, especially in those muscles that normally have a load-bearing function. The present study was designed to evaluate the effect of intermittent periods of weight support in ameliorating this atrophic response. Adult male Sprague-Dawley rats were assigned to either a control (CON), a hindlimb suspended (HS), or a hindlimb suspended plus intermittent weight support (HS-WS) group. HS-WS rats were walked slowly on a treadmill at 0.2 m/s and a 19{\%} incline for 10 min, every 6 h. After 7 d, the in situ mechanical properties of the soleus (Sol) and medial gastrocnemius (MG) were studied. Body weights of HS and HS-WS rats were 9 and 13{\%} lower than CON. The Sol weight relative to body weight was 21 and 9{\%} lower in HS and HS-WS than CON. Maximum tetanic tension relative to muscle mass was significantly lower in HS than CON, whereas HS-WS had values similar to CON. The MG weight relative to body weight was significantly lower in both suspended groups. The maximun tetanic tension relative to muscle weight was significantly lower in both suspended groups. The maximum tetanic tension relative to muscle weight was significantly elevated in HS-WS compared to CON, suggesting that weight support may have preferentially maintained the contractile protein component of the muscle. Contraction times were 25{\%} faster (p<0.05) in the Sol and unchanged in the MG of HS rats. For each muscle, the fatigue properties were similar in all groups. These data indicate that a low-force, short-duration exercise regime results in a significant functional recovery in the 'slow' Sol, whereas the 'fast' MG is less affected. Further, these data indicate that the amount and/or intensity of exercise necessary to maintain the functional integrity of the Sol appears to be minimal.",
author = "Pierotti, {David J} and Roy, {R. R.} and V. Flores and Edgerton, {V. R.}",
year = "1990",
language = "English (US)",
volume = "61",
pages = "205--210",
journal = "Aerospace medicine and human performance",
issn = "2375-6314",
publisher = "Aerospace Medical Association",
number = "3",

}

TY - JOUR

T1 - Infuence of 7 days of hindlimb suspension and intermittent weight support on rat muscle mechanical properties

AU - Pierotti, David J

AU - Roy, R. R.

AU - Flores, V.

AU - Edgerton, V. R.

PY - 1990

Y1 - 1990

N2 - Unloading the rat hindlimb results in a decrease in mass, especially in those muscles that normally have a load-bearing function. The present study was designed to evaluate the effect of intermittent periods of weight support in ameliorating this atrophic response. Adult male Sprague-Dawley rats were assigned to either a control (CON), a hindlimb suspended (HS), or a hindlimb suspended plus intermittent weight support (HS-WS) group. HS-WS rats were walked slowly on a treadmill at 0.2 m/s and a 19% incline for 10 min, every 6 h. After 7 d, the in situ mechanical properties of the soleus (Sol) and medial gastrocnemius (MG) were studied. Body weights of HS and HS-WS rats were 9 and 13% lower than CON. The Sol weight relative to body weight was 21 and 9% lower in HS and HS-WS than CON. Maximum tetanic tension relative to muscle mass was significantly lower in HS than CON, whereas HS-WS had values similar to CON. The MG weight relative to body weight was significantly lower in both suspended groups. The maximun tetanic tension relative to muscle weight was significantly lower in both suspended groups. The maximum tetanic tension relative to muscle weight was significantly elevated in HS-WS compared to CON, suggesting that weight support may have preferentially maintained the contractile protein component of the muscle. Contraction times were 25% faster (p<0.05) in the Sol and unchanged in the MG of HS rats. For each muscle, the fatigue properties were similar in all groups. These data indicate that a low-force, short-duration exercise regime results in a significant functional recovery in the 'slow' Sol, whereas the 'fast' MG is less affected. Further, these data indicate that the amount and/or intensity of exercise necessary to maintain the functional integrity of the Sol appears to be minimal.

AB - Unloading the rat hindlimb results in a decrease in mass, especially in those muscles that normally have a load-bearing function. The present study was designed to evaluate the effect of intermittent periods of weight support in ameliorating this atrophic response. Adult male Sprague-Dawley rats were assigned to either a control (CON), a hindlimb suspended (HS), or a hindlimb suspended plus intermittent weight support (HS-WS) group. HS-WS rats were walked slowly on a treadmill at 0.2 m/s and a 19% incline for 10 min, every 6 h. After 7 d, the in situ mechanical properties of the soleus (Sol) and medial gastrocnemius (MG) were studied. Body weights of HS and HS-WS rats were 9 and 13% lower than CON. The Sol weight relative to body weight was 21 and 9% lower in HS and HS-WS than CON. Maximum tetanic tension relative to muscle mass was significantly lower in HS than CON, whereas HS-WS had values similar to CON. The MG weight relative to body weight was significantly lower in both suspended groups. The maximun tetanic tension relative to muscle weight was significantly lower in both suspended groups. The maximum tetanic tension relative to muscle weight was significantly elevated in HS-WS compared to CON, suggesting that weight support may have preferentially maintained the contractile protein component of the muscle. Contraction times were 25% faster (p<0.05) in the Sol and unchanged in the MG of HS rats. For each muscle, the fatigue properties were similar in all groups. These data indicate that a low-force, short-duration exercise regime results in a significant functional recovery in the 'slow' Sol, whereas the 'fast' MG is less affected. Further, these data indicate that the amount and/or intensity of exercise necessary to maintain the functional integrity of the Sol appears to be minimal.

UR - http://www.scopus.com/inward/record.url?scp=0025194718&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0025194718&partnerID=8YFLogxK

M3 - Article

VL - 61

SP - 205

EP - 210

JO - Aerospace medicine and human performance

JF - Aerospace medicine and human performance

SN - 2375-6314

IS - 3

ER -