Villa P, Arioli P, Guaitani A
C. N. R. Center of Cytopharmacology, Department of Pharmacology, Milan, Italy.
In Vitro Cell Dev Biol. 1992 Mar;28A(3 Pt 1):157-60. doi: 10.1007/BF02631085.
Hepatocytes isolated from rats bearing line A of Walker 256 carcinoma (WA) were used to study the turnover of total liver protein and the synthesis of albumin in comparison with ad libitum (AL) and pair-fed (PF) healthy controls. The rates of total protein synthesis by hepatocytes of WA animals were 40 and 90% higher than in AL and PF controls, respectively. The degradation of fast-turnover proteins was not affected by nutrition or by the tumor, whereas the degradation of slow-turnover proteins was slightly but significantly increased--about 24% higher in hepatocytes from WA rats than in PF controls. The combination of the two processes, synthesis and degradation, was in favor of an increased synthesis which explains the increase in liver protein content observed in vivo in WA rats. Dietary restriction did not affect the synthesis and secretion of albumin, whereas the tumor significantly reduced its synthesis by about 30%. The plasma concentration of albumin in WA rats dropped by about the same percentage compared with AL and PF animals.
从携带Walker 256癌A系（WA）的大鼠中分离出肝细胞，与自由采食（AL）和配对喂养（PF）的健康对照相比，用于研究肝脏总蛋白的周转和白蛋白的合成。WA动物肝细胞的总蛋白合成速率分别比AL和PF对照高40%和90%。快速周转蛋白的降解不受营养或肿瘤的影响，而缓慢周转蛋白的降解略有但显著增加——WA大鼠肝细胞中的降解比PF对照高约24%。合成和降解这两个过程的结合有利于合成增加，这解释了在WA大鼠体内观察到的肝脏蛋白含量增加。饮食限制不影响白蛋白的合成和分泌，而肿瘤显著降低其合成约30%。与AL和PF动物相比，WA大鼠的血浆白蛋白浓度下降了约相同的百分比。
