The mechanisms responsible for the morphological and metabolic adaptation of skeletal muscles to the removal of antigravity activity were investigated in @entity35 . Significant atrophy relative to the levels before suspension was induced in ankle plantarflexsors, may be due to a reduced tension production caused by decreased muscle length and electromyogram activity. @entity851 was significant in ankle dorsiflexors, although these muscles did not atrophy. Forced muscle contraction through electrical stimulation at 1 or 100 Hz during hind limb suspension generally had detrimental effects. The percent contribution of water loss to the suspension-related change in weight was 85, 88, and 93% in soleus, plantaris, and extensor digitorum longus, respectively. The total levels of both @entity19137 dehydrogenase (HAD) and @entity880 dehydrogenase (LDH) were less in the suspended muscles than in the controls, having high positive correlations with the total protein content. The specific activity of HAD, but not of LDH, of the suspended muscles was lower than in the controls (25-61%). These data suggest that the cause of @entity2057 and changes in metabolic properties may be a decreased tension development, not necessarily the reduction of electrical or contractile activity. Further, it is clearly suggested that electrical stimulation of a muscle group with different composition of fiber phenotype at a certain pattern or frequency is not suitable for the countermeasure. It is also suggested that the major cause of the decreased muscle weight was loss of water, even though protein content was also lowered after suspension. Moreover, the data suggest that the HAD level was affected more than the total protein content and LDH.

Regulation of the properties of XXXX hind limb muscles following gravitational unloading.

@entity851 :: ('MESH:D006130', 'Disease') :: ['Growth failure'] @entity19137 :: ('CHEBI:20060', 'Chemical') :: ['beta-hydroxyacyl CoA'] @entity880 :: ('MESH:D019344', 'Chemical') :: ['lactate'] @entity35 :: ('10116', 'Species') :: ['rats'] @entity2057 :: ('MESH:D009133', 'Disease') :: ['muscle atrophy']
@entity35 :: (10116,Species) :: ['rat']
