Organ culture of frog muscle: maintenance of mass, enzyme levels, and contractile force.
This paper describes an organ culture system that maintains frog sartorius muscles in good condition for 5 days. In the absence of serum and insulin, muscles maintained at approximately 93% of resting length atrophied with significant decreases in dry weight, protein content, and contractile force, and in the levels of activity of citrate synthase, lactate dehydrogenase, and creatine kinase. Inclusion of 1.0 mU/ml of insulin in the culture medium prevented the decreases in muscle mass, twitch tension, and citrate synthase activity and minimized the decreases in lactate dehydrogenase, creatine kinase, and tetanic tension. Inclusion of 10% serum, in addition to 1 mU/ml insulin, in the medium did not have clear cut additional benefits. Stretching muscles to 110% of resting length (L0) resulted in marked deterioration with decreases in total protein, enzyme levels, and contractile force. Keeping muscles at approximately 93% L0 was as effective as maintenance at L0 in preventing atrophy and loss of contractile force and enzyme activities. This organ culture procedure, which maintains frog sartorius muscle in good condition without serum for at least 5 days, may provide a useful model for studying the regulatory mechanisms responsible for a variety of adaptations in muscle.
Ohira
Y
Y
Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.
Ohira
M
M
Chen
M
M
Holloszy
J O
JO
D000818:Animals; D009119:Muscle Contraction; D009132:Muscles / Q000201:enzymology; D009924:Organ Culture Techniques / Q000379:methods; D011894:Rana pipiens