Rice F A, Oresajo C, Heath J R, Breyere E J, McCurdy J D
Cancer Res. 1981 Dec;41(12 Pt 1):4976-80.
It was found that inoculation of several strains of mice with several types of tumor cells resulted, within 24 hr, in a significant decrease in the serum leucogenenol levels of the mice. Serum leucogenenol levels of the mice inoculated with tumors that are rejected become normal or temporarily above normal at approximately the time the tumor is observed to be rejected. Contrariwise, serum leucogenenol levels of mice inoculated with tumors that are not rejected remain at significantly lower than normal levels during the life of the mice. Unlike tumors, skin allografts increase serum leucogenenol levels. When tumors are rejected because of the previous immunization of the mice, serum leucogenenol levels become normal at approximately the time the tumor is observed to be rejected. Excision of the tumor after 1 week of growth, with the consequent recovery of the mice, is accompanied by a recovery of normal serum leucogenenol levels. Also, it was found that injection of mice with a cell-free 0.9% NaCl solution extract of a tumor results in a temporary decrease in serum leucogenenol levels comparable to that observed with the inoculation of a viable tumor which lasts from 24 to 96 hr. It is suggested that the suppression of serum leucogenenol levels is one of the factors responsible for the immunosuppression associated with a growing tumor.
研究发现，给几种品系的小鼠接种几种类型的肿瘤细胞后，在24小时内，小鼠血清亮氨酸生成醇水平显著降低。接种后被排斥肿瘤的小鼠血清亮氨酸生成醇水平在观察到肿瘤被排斥时恢复正常或暂时高于正常水平。相反，接种后未被排斥肿瘤的小鼠血清亮氨酸生成醇水平在小鼠存活期间一直显著低于正常水平。与肿瘤不同，皮肤同种异体移植物会使血清亮氨酸生成醇水平升高。当小鼠因先前的免疫作用而排斥肿瘤时，血清亮氨酸生成醇水平在观察到肿瘤被排斥时恢复正常。肿瘤生长1周后切除，随后小鼠恢复，同时血清亮氨酸生成醇水平也恢复正常。此外，研究发现给小鼠注射肿瘤的无细胞0.9%氯化钠溶液提取物会导致血清亮氨酸生成醇水平暂时降低，这与接种活肿瘤后观察到的情况类似，持续时间为24至96小时。有人认为，血清亮氨酸生成醇水平的抑制是与肿瘤生长相关的免疫抑制的原因之一。
