Changes in peripheral serum creatine phosphokinase (CPK) and lactic dehydrogenase (LDH) in acute experimental colonic infarction

No satisfactory laboratory test for the early diagnosis of bowel infarction exists at this time. We have delineated changes in serum CPK levels after acute superior mesenteric artery infarction; whether or not comparable changes occur with inferior mesenteric artery infarction has not yet been determined. Furthermore, the changes in LDH associated with acute bowel infarction have not been documented. To determine the changes in serum CPK and LDH in acute colonic infarction, laparotomies were performed on dogs after peripheral baseline blood samples were drawn and each subject was randomly placed in one of three groups: laparotomy alone, acute colonic obstruction, and acute colonic infarction by ligation of the inferior mesenteric artery. The marginal artery of the colon was ligated at the peritoneal reflection and at the cecum to interrupt arterial collaterals. Blood samples were taken from each subject at intervals of three hours for 48 hours after injury. Serum from each sample was analyzed for total CPK and LDH by automated spectrophotometry. Isoenzymes were determined by agarose gel electrophoresis. Necropsies were conducted on all the dogs to confirm that the intended condition had been produced and that no intercurrent disease was present. The data support the conclusion that total CPK, total LDH and their isoenzymes become elevated in the peripheral serum after colonic infarction. The maximal elevations were all seen within the first 12 hours after acute colonic infarction. Total LDH and LDH₃, the most prevalent isoenzyme of LDH in bowel, do not become elevated in the serum to as high a level as CPK, but the combination of serum elevations in both enzyme systems may prove to be of diagnostic significance.