Human heart-type cytoplasmic fatty acid-binding protein as an indicator of acute myocardial infarction.
Human heart-type cytoplasmic fatty acid-binding protein (HH-FABPc) has been proposed as an early biochemical indicator of acute myocardial infarction (AMI). However, skeletal muscles also contain HH-FABPc identical to that found in the heart. Before HH-FABPc can be clinically employed as an indicator of AMI, its content in various tissues other than the heart must be known. Accordingly, we measured the HH-FABPc content of various human muscles and organs, using a sandwich enzyme-linked immunosorbent assay (ELISA) for HH-FABPc. HH-FABPc was abundant in the ventricles (0.46 mg/g wet weight and 1.5% of the cytoplasmic protein in the left ventricle), while the atria contained slightly less HH-FABPc (0.25 mg/g wet weight and 0.7% of the cytoplasmic protein in the left atrium). Of the skeletal muscles tested, the diaphragm contained about one-quarter of the HH-FABPc content of the heart, but other skeletal muscles contained very low levels of this protein. Other than the muscles, the kidneys contained less than one-tenth of the HH-FABPc in the heart, and negligible amounts were found in the liver and small intestine. The distribution of HH-FABPc in the heart and skeletal muscles was comparable to that of cardiac-specific creatine kinase (CK-MB) activity, and was inverse to the distribution of myoglobin. The plasma myoglobin/HH-FABPc ratio, determined in patients with AMI and those without AMI, closely reflected that in the heart and skeletal muscles. These findings indicate that HH-FABPc may be useful as a specific indicator of AMI, and the plasma myoglobin/HH-FABPc ratio could provide valuable information for the diagnosis of AMI.
Yoshimoto
K
K
Department of Internal Medicine, Osaka Medical College, Japan.
Tanaka
T
T
Somiya
K
K
Tsuji
R
R
Okamoto
F
F
Kawamura
K
K
Ohkaru
Y
Y
Asayama
K
K
Ishii
H
H
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D002352:Carrier Proteins / Q000378:metabolism*; D003402:Creatine Kinase / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005260:Female; D006801:Humans; D007421:Intestine, Small / Q000378:metabolism; D007527:Isoenzymes; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism; D009132:Muscles / Q000378:metabolism*; D018996:Myelin P2 Protein / Q000378:metabolism*; D009203:Myocardial Infarction / Q000175:diagnosis / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D009211:Myoglobin / Q000378:metabolism; D009363:Neoplasm Proteins; D012680:Sensitivity and Specificity; D025521:Tumor Suppressor Proteins
D015415:Biomarkers; D002352:Carrier Proteins; C107608:FABP7 protein, human; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D007527:Isoenzymes; D018996:Myelin P2 Protein; D009211:Myoglobin; D009363:Neoplasm Proteins; D025521:Tumor Suppressor Proteins; D003402:Creatine Kinase