Lactate Dehydrogenase in the Swimming Muscles of the Cartilaginous Fish Chimaera monstrosa

Two LDH isoenzymes are present in the swimming muscles of Chimaera. The axial muscle, consisting almost exclusively of white fibres, has most of the slow-migrating isoenzyme, while pectoral muscle, rich in red fibres, have most fast-migrating isoenzyme. The LDH activity is not visibly affected by 2 M urea, but is nearly extinguished by 4 M urea.