[Effects of soy isoflavone on gene expression of resistin in insulin-resistance rats].
OBJECTIVE
To assess the effects of soy isoflavone (SIF) on improving insulin reistance (IR) status in IR rats induced by high-fat and high-sugar diet and explore the possible mechanisms.


METHODS
IR rats were randomly divided into four groups according to their insulin resistance indices (IRI). The rats in one model control group and three SIF groups were fed via gavage with water solutions containing SIF at doses of 0 mg/ kg x bw, 50 mg/kg x bw, 150 mg/kg x bw, and 450 mg/kg x bw, respectively. After one month, fasting glucose, fasting insulin, resistin in serum, and resistin mRNA in adipocyte around kidney were detected by enzymologic method, radioimmunoassay, enzyme linked immunosorbent assay, and real time RT-PCR, respectively.


RESULTS
Comparison between the model control group and the other groups revealed that serum resistin and resistin mRNA expression levels were lower in the 450 mg/kg x bw group, that insulin and IRI levels were lower in the 150 mg/ kg x bw group and 450 mg/kg x bw group, and that no differences in plasma glucose levels existed among the 4 groups. A positive correlation between IRI and serum resistin level (r = 0.355, P < 0.05) was observed.


CONCLUSIONS
These results suggest that soy isoflavone may down-regulate resistin mRNA expression, decrease serum resistin level and enhance insulin sensitivity.
Chen
Shi-wei
SW
Department of Nutrition and Food Hygiene, West China School of Public Health, Sichuan University, Chengdu 610041, China.
Zhang
Hong-min
HM
Zhang
Li-shi
LS
Feng
Xiao-fan
XF
D000818:Animals; D007333:Insulin Resistance / Q000235:genetics*; D007529:Isoflavones / Q000494:pharmacology*; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D052243:Resistin / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics; D013025:Glycine max / Q000737:chemistry*
D007529:Isoflavones; D012333:RNA, Messenger; D052243:Resistin; C065753:isoflavanone