Lactic dehydrogenase (LDH) is an enzyme which catalyzes the reversible oxidation oflactic to pyruvic acid. This report deals with a study of clinical significance of Serum Lactic dehydrogenase (LDH) in surgical disorders. LDH activity in serum was measured colorimetrically by themethod of Cabaud and Wroblewski and LDH isozyme pattrens was obtained with a starch gelelectrophoresis technique by the method of Wieme. The results are summarized as follows: 1) Serum LDH activity increased in gastric cancer and other malignant conditions, especially in liver metastasis. 2) Serum LDH activity was insignificant for diagnosis in the primary condition of thegastric cancer. 3) Operative removal of malignant tumor was not followed by an immediate decreaseof serum LDH activity. 4) Serum LDH activity was increased in hepatoma and markedly in metastatic cancerof the liver. 5) Serum LDH activity was increased highly in recurrence of malignant tumors. 6) In cholelithiasis serum LDH activity increased slightly to moderately with affected liverfunction tests. 7) The isozyme pattern of serum LDH in primary and metatatic carcinoma of the livershowed in marked increase of LDH-I. 8) Marked increase of Serum LDH activity and LDH-I in serum LDH isozyme may leadto the diagnosis of liver metastasis.
The author attempted to investigate the relationship between the serum iodic acid reducingpower and the pattern of serum protein in the dogs with hepatic injury and in the patientswith liver diseases respectively. The dogs used in the experiment were devided into twogroups; the one was the moderate and the other was advanced liver injury by intramuscularinjection of carbontetrachloride. The results obtained were as follows: 1) The serum iodic acid reducing power were 0.174±0.026 in normal dogs and 0.167±0.036 in healthy persons. 2) In the dogs with moderate liver injury the serum iodic acid reducing power droppedon the first day, rised up to the maximum on the third day, dropped again on the fifth day andthen went gradually up to the value before the administration of carbontetrachloride. On theother hand, in the dogs with advanced liver injury the serum iodic acid reducing power risedup to maximum on the second day and then fell gradually, but remained in high value evenon the fourteenth day. The changes of the serum iodic acid reducing power in the dogs withhepatic injury were associated with the histrogical findings of the liver, however the authorshould like to consider that the initial drop of the serum iodic acid reducing power in thedogs with moderate liver injury was due to the disharmony of the liver function.3) The serum iodic acid reducing power in the patients with liver diseases showed a highor low value with the drop of A/G ratio as compared with that of healthy persons. When A/Gratio showed a low value, the serum iodic acid reducing power was found to be abnormalalthough other important tests of liver function revealed abnormal findings, and when A/Gratio was within normal limits, the serum iodic acid reducing power was within normal limitsalthough the results of other function tests were abnormal. From the results above mentioned, the variation of serum iodic acid reducing power inhepatic injury was considered to reflect the changes of the pattern of serum protein and alsoto be based on the disharmony of the liver function.