Journal of Applied Physiology, Vol 67, Issue 1 466-471, Copyright © 1989 by American Physiological Society
Organ culture of frog muscle: maintenance of mass, enzyme levels, and contractile force
Y. Ohira, M. Ohira, M. Chen and J. O. Holloszy
Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.
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.
