Examinations
Examinations
Lactate dehydrogenase (LDH) is a glycolytic enzyme involved in the final stages of glucose metabolism, catalyzing the reversible conversion of lactate to pyruvate.
Key Characteristics:
- Zinc-dependent enzyme: Predominantly found in the cytoplasm.
- Wide tissue distribution: Present in nearly all tissues and organs, with high activity in the kidneys, liver, heart, skeletal muscles, pancreas, and blood cells. LDH levels in red blood cells are 100 times higher than in serum.
- Age-dependent activity: Higher LDH levels are observed in children, with levels decreasing as they age.
- Physiological increases: Observed during pregnancy, in newborns, and after physical exertion.
Clinical Relevance:
- After a heart attack:
- LDH levels begin to rise 12–24 hours post-myocardial infarction.
- Peak activity occurs within 24–48 hours and remains elevated for up to 10 days.
- LDH activity is directly related to the extent of myocardial damage, with its decline corresponding to the rate of healing in the heart muscle.
The test is performed on a blood sample taken from a vein.
- The test should be conducted after 8–14 hours of fasting.
- It can also be done 4 hours after a light meal.
- Avoid physical and emotional stress and alcohol consumption before the test.
- Diseases of the hepatobiliary system
- Myocardial infarction (early diagnosis, differential diagnosis, and monitoring)
- Tumors
- Anemia with hemolysis
- Liver pathologies
- Myocardial infarction and lung infarction
- Malignant tumors
- Atrophy of striated muscle, trauma
- Acute pancreatitis
- Alcohol consumption and use of certain medications (e.g., caffeine, anesthetics, cephalosporins, sulfonamides, etc.)