Effect of centrifugation at 2G for 14 days on metabolic enzymes of the tibialis anterior and soleus muscles.
BACKGROUND
The enzyme composition of different muscle types vary greatly, leading to different changes of enzyme level caused by exposure to various stimuli.


METHODS
Male Wistar rats were centrifuged at 2G in a 12-ft radius centrifuge for 14 d. Tibialis anterior (TA) and soleus muscles from four centrifuge and four control rats were analyzed for three enzymes characteristic of fast twitch muscles (phosphofructokinase, glycerol-3-phosphate dehydrogenase, and pyruvate kinase), and four enzymes characteristic of slow twitch muscles (hexokinase, mitochondrial thiolase, B-hydroxyacyl CoA dehydrogenase, and citrate synthase).


RESULTS
The centrifuged TA muscles lost 15% of their weight; the corresponding soleus muscles gained 4%. Calculated on the basis of dry weight, the fast twitch enzyme activities were reduced 3-15% in the TA muscles but increased 10-23% in the soleus muscles. The slow twitch enzymes were reduced 18-30% in TA muscles but were almost unchanged in the soleus muscles. When calculated on the basis of total muscle weight, all of the enzymes in TA muscles were significantly reduced by centrifugation. In contrast, in soleus muscles, on the basis of total muscle weight, centrifugation caused an average increase of 22% in the fast twitch enzymes but only marginal changes in the slow twitch enzymes.
Chi
M M
MM
Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Manchester
J K
JK
Lowry
O H
OH
D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000032:analysis; D000101:Acetyl-CoA C-Acetyltransferase / Q000032:analysis; D000818:Animals; D001835:Body Weight / Q000502:physiology; D002498:Centrifugation / Q000009:adverse effects*; D002950:Citrate (si)-Synthase / Q000032:analysis; D005993:Glycerolphosphate Dehydrogenase / Q000032:analysis; D006593:Hexokinase / Q000032:analysis; D018471:Hypergravity / Q000009:adverse effects*; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000737:chemistry* / Q000201:enzymology*; D009929:Organ Size; D010732:Phosphofructokinase-1 / Q000032:analysis; D011770:Pyruvate Kinase / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D005993:Glycerolphosphate Dehydrogenase; D015094:3-Hydroxyacyl CoA Dehydrogenases; D000101:Acetyl-CoA C-Acetyltransferase; D002950:Citrate (si)-Synthase; D006593:Hexokinase; D010732:Phosphofructokinase-1; D011770:Pyruvate Kinase