[Lactate dehydrogenase isoenzyme in Rous sarcoma and muscle tissue of tumor-bearing hens]. 
The isoenzymic spectrum and lactate dehydrogenase activity (LDH) were studied in tumor and pectoral muscle of both chicken and adult hens on the 6th, 10th and 15th day after their infection with the Rous sarcoma virus.  On the 14th day, unlike the muscles of intact hens, in the tumour the content of LDH-5 increases and that of rapidly migrating fraction LDG-1 and LDG-2 decreases.  In pectoral muscles unaffected by the tumour (on the opposite side of the sternum) there is a tendency to an increase in LDH-4 content and to a decrease in LDH-1 and LDG-2 content, which is followed by a decreasing proportion of N/M subunits.