Improved column method for separating lactate dehydrogenase isoenzymes 1 and 2.

Area of Science:

• Biochemistry
• Clinical Chemistry
• Cardiology

Background:

• Lactate dehydrogenase (LD) is an enzyme found in various tissues.
• LD isoenzymes, particularly LD-1 and LD-2, can indicate tissue damage.
• Distinguishing between LD isoenzymes is crucial for diagnosing conditions like myocardial infarction.

Purpose of the Study:

• To develop and validate a method for separating and quantifying lactate dehydrogenase isoenzymes 1 and 2 in human serum.
• To evaluate the diagnostic utility of the LD-1/LD-2 ratio for acute myocardial infarction.

Main Methods:

• Serum samples were fractionated using diethylaminoethyl-Sephadex mini-columns eluted with buffered sodium chloride.
• Lactate dehydrogenase activity was measured using the Wacker method.
• Isoenzyme content was confirmed via polyacrylamide gel electrophoresis.

Main Results:

• The LD-1/LD-2 ratio proved to be a more specific indicator of myocardial infarction than total LD activity.
• Patients with acute myocardial infarction (indicated by elevated creatine kinase isoenzyme MB) showed LD-1/LD-2 ratios between 0.92 and 1.56.
• Control patients without heart disease had LD-1/LD-2 ratios ranging from 0.33 to 0.69.

Conclusions:

• The LD-1/LD-2 ratio is a valuable and specific biomarker for diagnosing acute myocardial infarction.
• This method offers a reliable way to differentiate cardiac events from other conditions based on enzyme profiles.