| Research Abstract |
When the brain is damaged, some constituents of the brain may leak into the cerebrospinal fluid. Therefore, the measurement of leakage may be useful for the diagnosis of brain damage. In fact, several brain specific proteins were reported to be useful as biochemical markers of brain damage. Three of them, gamma-enolse (a neural marker), S-100b protein (a glial marker) and creatine kinase BB (CKB, marker of both neurons and glias), were compared with each other of their usefulness as the biochemical marker of brain damage. As an animal model of brain damage, jaundiced rats (Gunn rats) were used. At 7 days of birth, those rats were injected with bucolome, a potent displacer of bilirubin from albumin. After 16-20 hours, the animals were very sick due to kernicterus. Cerebrospinal fluid was sampled from the animals and leakage of the brain proteins into the cerebrospinal fluid was measured by an enzyme immunoassay. Gamma-enolase was elevated up to 30 times as high as that of normal level. Elevation of CKB was also remarkable, but not so high as in the case of gamma-enolase. S-100 protein did not increase in despite of the brain damage. These results suggest that neuron-specificity is an essential factor for a good molecular marker of neural damage. Based on this observation, usefulness of a new marker protein, Goalpha-protein which showed very high neuron-specificity in our previous study, was examined. In a similar experiment using Gunn rat, Goalpha in the cerebrospinal fluid of sick animals was remarkably high, but not so high as in the case of gamma-enolase. This result suggests that solubility of the marker protein into the cerebrospinal fluid is also an important factor. In summary, gamma-enolase was the best marker among the four marker proteins tested.
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