諸種疾患患者の血漿中亜鉛および銅量に関する知見 : ことに悪性腫瘍について

抄録

Many biochemical studies on the zinc and copper contents in the plasma of patients with malignant tumors and other diseases have been reported in the literatures. However, no definite conclusion has not yet been reached as to what changes could occur in the plasma zinc and copper contents in patients with malignant tumors, nor was there any report on the related subject in the field of oral surgery. The present author undertook to determine the plasma contents of both zinc and copper in 314 subjects suffering from a variety of disease including various types of malignant tumors. The trace metals were determined by use of atomic absorption spectrophotometry (Nippon Jarrell-Ash). In each determination of the metals a single sample of blood plasma was used. The plasma zinc level of the normal group was 1.14 ± 0.21 μg/ml, while the copper level was 0.95 ± 0.21 μg/ml. In the malignant group including 21 cases of malignancy in the oral region, the content of plasma zinc was 0.99 ± 0.22 μg/ml, and that of plasma copper 1.36 ± 0.30 μg/ml. The latter value was higher and the former was lower respectively than the corresponding values obtained from normal group with high significance (p<0.001). In an attempt to get an index of these two variables, the ratio of copper and zinc contents (Cu/Zn ratio) was calculated with all of the determinations. The result showed that the Cu/Zn ratio from the normal group fell in the range of 0.86 ± 0.14, while the one from the malignancy group rose to 1.43 ± 0.36. This difference in the indices between the normal and malignancy groups was statistically significant. It should be further noticed that 96.9% of the cancer group showed Cu/Zn ratio higher than 1.00, while only 9.8% of the normal group showed the ratio higher than 1.00, although 50.0% of the malignancy group demonstrated a lower level of plasma zinc than the normal rnge, and 77.6% of the group showed a higher level of plasma copper than the normal range. These indices tended to rise higher with progressive severity of malignancy. On the other hand, the Cu/Zn ratio higher than 1.00 was observed in high frequency not only in the group with malignancy, but also in groups of hepato-biliary diseases, renal diseases, appendicitis and pregnancy. Thus, those who gave the Cu/Zn ratio higher than 1.00 were not always limited to the group with malignancy. But the disturbance of the hepatic or renal function. Of course, the further study would be necessary to evaluate the Cu/Zn ratio from the viewpoint of cancer diagnosis. Nevertheless, it should be emphasized in the study of cancer metabolism that the cancer group in distinguished far more clearly from the normal group by the Cu/Zn ratio than by either copper or zinc level in the plasrna, and that the grade by the Cu/Zn ratio than by either copper or zinc level in the plasma, and that the grade of the advancement of the carcinoma was shown to have a close relationship with the ratio.