Changes of intracellular electrolyte contents in rat skeletal muscle during body suspension.
The CNS-mediated inhibition of active Na(+)-K+ transport in both "type S" muscle, soleus (SOL), and "type FF" muscle, extensor digitorum longus (EDL) was investigated in rats suspended horizontally. Plasma Na+ and K+ contents did not change during the suspension period. The relative wet weight of SOL decreased more than that of EDL by suspension. There was significant intracellular Na+ accumulation and K+ loss in both SOL and diaphragm of suspended rats. However, cerebrum, cerebellum, medulla oblongate, ventricle, liver, pancreas, kidney, intestine, aorta and EDL were spared from the intracellular Na+ accumulation and K+ loss. Sciatic nerve sectioning or cervical spinal cord transection recovered the Na+ and K+ contents in the SOL of suspended rats. The results indicate the existence of neural inhibition of the active Na(+)-K+ transport in skeletal muscle of the suspended rats.
Nagaoka
R
R
Department of Physical Education, College of Liberal Arts, Kagoshima University, Japan.
Mizuno
M
M
Yamashita
S
S
Akaike
N
N
D000818:Animals; D003714:Denervation; D017136:Ion Transport; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation / Q000378:metabolism*; D009133:Muscular Atrophy / Q000209:etiology; D011188:Potassium / Q000097:blood / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012584:Sciatic Nerve / Q000502:physiology; D012964:Sodium / Q000097:blood / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013116:Spinal Cord / Q000502:physiology; D014018:Tissue Distribution; D014893:Weightlessness / Q000009:adverse effects*
D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium