Total creatine kinase in serum

Reference values ​​of serum CC activity: men - 52-200 IU / l, women - 35-165 IU / l.

QA reversibly catalyzes the phosphorylation of creatine. The skeletal musculature, the heart muscle, is the richest in the KK, less in the brain, in the thyroid gland, in the uterus, in the lungs. The greatest diagnostic value is due to the following isozymes of QA: KK-MM( muscle), KK-MB( cardiac), KK-BB( cerebral).The increase in serum CK activity is due to the release of the enzyme from the cells when they are damaged.

With myocardial infarction, the entry of QA from the cardiac muscle to the serum leads to other enzymes, so the determination of QA has found the widest application for early diagnosis. The increase in activity of CC is detected in 95-99% of patients with MI.CC increases in 2-4 hours after the onset of the disease, reaching a maximum after 24-36 hours( 5-20 times higher than normal).It should be emphasized that the activity of QC comparatively quickly returns to normal( on the 3rd-6th day).Changes in enzyme activity in MI are presented in the table.

Table Change in enzyme activity with AS AS244DD Table Change in enzyme activity with AS AS2525DD Increased activity of QC in the blood can not be considered a specific feature of myocardial infarction. The activity of QA can increase with myocarditis, myo-cardiodystrophy of various origin. Nevertheless, in these cases, the enzyme is moderate, longer, and usually corresponds to the phase of maximum activity of the process. A significant increase in

activity in the serum is observed in traumatic lesions of skeletal muscles and muscular system diseases. So, with progressive muscular dystrophy( myopathy), the activity of QA can increase 50 times or more in comparison with the norm, which is used as a diagnostic test. It should be noted that with neurogenic dystrophies, the activity of QA in the blood often remains within normal limits. In order to differentiate MI from muscle damage, determine the ratio of KK / AST.With MI, this ratio is less than 10;if it is more than 10, then we can talk about the damage to skeletal muscles.

High activity of QC is possible with various disorders of the central nervous system( schizophrenia, manic-depressive psychosis, syndromes caused by psychotropic drugs, etc.).In addition, the activity of QC increases after various surgical operations, and the method and duration of anesthesia affects the postoperative level of CC activity.

Finally, it should be borne in mind that the increase in activity of QA is possible with alcohol intake and after the administration of drugs that activate the enzyme( for example, prednisolone) and hypothyroidism( on the contrary, when TSH is unusually low in thyrotoxicosis).