1) A Lineweaver-Burk plot of tryptophan aminotransferase activity in the supernatant fraction from rat liver gave a hyperbolic curve. This suggested that the activity might be due to the simultaneous actions of two or more enzymes with different Km values.2) On DEAE-cellulose column chromatography of the supernatant from normal rat liver, tryptophan aminotransferase activity separated into two peaks, while that from the liver of rats after tryptophan or cortisol injection separated into three peaks. The second peak eluted from the latter seems to be an inducible enzyme. No aspartate, alanine, tyrosine, kynurenine, histidine or phenylalanine aminotransferase activities were detected in this fraction. The first peak eluted from DEAE-cellulose column had aspartate aminotransferase activity and the third peak had tyrosine aminotransferase activity.3) On DEAE-cellulose column chromatography, the tryptophan aminotransferase activity in the supernatant fractions from the kidneys and hearts of normal rats, tumor cells (AH-130) and the livers of tumor-bearing rats showed the same elution pattern as that from the liver of rats after tryptophan or cortisol injection. The Km values for tryptophan of these enzymes in the second peaks were all similar. These results suggest that the aminotransferase enzyme in the second peaks from all these sources may be the same kind of tryptophan specific enzyme.In 1958 Lin et al. reported the methods for assay of aromatic amino acid aminotransfe rases, and the results investigated on the activity of tryptophan aminotransferase (1). However, it is . still uncertain whether the activity of tryptophan:2-oxoglutarate aminotransferase is due to a specific enzyme for tryptophan or side actions of other aminotransferases. We examin ed on this problem and found that the activity of tryptophan:2-oxoglutarate aminotransferase in rats consists of three components: one is due to a specific tryptophan aminotransferase and the others to side actions of other aminotrans ferases. We also studied the properties of the specific tryptophan aminotransf erase.
SummaryA 31-year-old woman underwent cervical laminectomy for decompression and diagnosis of syringomyelia which involved the higher cervical cord. After surgery, the patient complained of paresthesia with severe deep pain which appeared in her feet and migrated upwards in succession to her hands. At the same time, the patient suffered intense muscle spasms which started in the sternocleidomastoid and migrated down wards in succession to her legs. These attacks occurred all day, repeatedly, at intervals of 120 to 300 sec. Based on electrophysiological analysis, these attacks were considered to be due to abnormal discharges which developed in the lesion in the cervical cord, and stimulation of the pathways showing somatotopic laminations in the cord. Electrical stimulation of the median nerve at the wrist was effective against these attacks and complete remission was obtained by diphenylhydantoin administration.
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