The Annals of Thoracic Surgery, Vol 32, 230-234, Copyright © 1981 by The Society of Thoracic Surgeons
An analysis of the isoenzymes of creatine phosphokinase and lactic dehydrogenase in the esophagus
GM Graeber, MJ Reardon, AW Fleming, HD Head, R Zajtchuk, WH Brott and JH Foster
Surgical manipulation of muscular organs can cause alterations of the serum
isoenzymes of creatine phosphokinase (CPK) and lactic dehydrogenase (LDH),
which are frequently used to confirm the diagnosis of myocardial infarction
(MI). Since the content of these enzymes and their isoenzymes has not been
established for the esophagus, an experiment was conducted to evaluate and
compare the enzymes in postmortem specimens from humans and fresh canine
specimens. One gram transmural esophageal sections were taken from
specimens having no demonstrable disease. All samples were homogenized
individually in Ringer's lactate solution and centrifuged, and the
supernatants were analysed for the respective isoenzyme distributions by
agarose gel electrophoresis. From the study we drew the following
conclusions: (1) all three isoenzymes of CPK (including CPK-MB, the
myocardialisoenzyme) are present in the esophagus; (2) LDH, the isoenzyme
of LDH most prevalent in myocardium, is the least common of the five
isoenzymes of LDH in the esophagus; (3) the dog is an appropriate model for
studying changes of these isoenzymes after operation; and (4) any potential
confusion in diagnosing postoperative MI due to esophageal CPK-MB in the
serum can be resolved, theoretically, by analyzing LDH serum isoenzymes. In
myocardial infarction, LDH becomes the predominant isoenzyme, whereas
esophageal injury should be associated, theoretically, with a serum LDH
isoenzyme pattern in which LDH is the least prevalent isoenzyme.