Effect of zinc deficiency on hepatic protein expression patterns in rats

Abstract

Zinc deficiency is an important public health problem in the world. Zinc deficiency causes metabolic abnormalities, probably in part due to the altered protein expression patterns. This study was aimed to investigate hepatic protein expression patterns in zinc deficient rats. Thirty 3-week-old male Sprague-Dawley rats were randomly divided into three groups and fed the respective diet for four weeks. The ad libitum-fed control group (CON) and the pair-fed group (PF) were given AIN-93G diet, and zinc-deficient group (ZD) was given zinc-deficient diet (zinc level 4.5 mg/kg). After dietary regimen, liver was excised under ethylether anesthesia and stored at −80 degree until analyses. Liver homogenate was subjected to 2-D PAGE. Gels were digitally scanned and intensity of protein spots was statistically analyzed by principal component analysis. The first and second components (PC1 and PC2) explained 45% and 32% of all variance, respectively. PC1 was significantly different among all three groups (P<0.001 by Fisher's PLSD). ZD was placed between CON and PF in terms of PC1. PC2 of ZD was significantly different from that of CON and PF (P<0.001), while PC2 was almost identical between CON and PF. These results suggest that PC1 is related to the response to diet restriction, and PC2 is related to zinc deficiency per se. Supported by Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research (C) (22500772).