Glucocorticoids decrease serum adiponectin level and WAT adiponectin mRNA expression in rats.
OBJECTIVE
Accumulating evidence suggests that adiponectin plays an important role in the genesis of obesity and insulin resistance. Although it has been shown that glucocortocoids (GC) inhibit adiponectin expression in vitro, there exist discrepant results in vivo. In this study, we observe the effect of GC on the serum adiponectin level and adiponectin expression in white adipose tissue (WAT) in male SD rats.


METHODS
An obese rat model was made by a high-fat diet. Both non-obese and obese rats were randomly divided into normal saline (intraperitoneal injection with normal saline 0.2ml/100gday for 20 days, NS), a low dose GC group (intraperitoneal injection with hydrocortisone sodium succinate 5mg/kgday for 20 days, LDG) and a high dose GC group, respectively (intraperitoneal injection with hydrocortisone sodium succinate 15mg/kgday for 20 days, HDG). Serum adiponectin levels were detected by ELISA and the adiponectin mRNA level was assayed by Northern blot.


RESULTS
The serum adiponectin level significantly decreased after 80 days of the high-fat diet (P<0.05), while it was not decreased after 80 days of the chow diet (P>0.05). The serum adioponectin levels in both the non-obese and obese rats were significantly decreased after a 20-day GC injection period (P<0.01). The adiponectin mRNA levels in epididymal fat after high dose GC injection, in both non-obese and obese rats were also decreased (P<0.001).


CONCLUSIONS
A high-fat diet decreased serum adiponectin levels in the rat. GC decreased serum adiponectin levels, and this might be due to inhibited adiponectin mRNA expression in WAT. High-fat diet and GC have a synergistic effect on inhibiting adiponectin expression in rats.
Shi
Jian-Hua
JH
Department of Endocrinology, The First Affiliated Hospital of Bangbu Medical College, 801 Zhihuai Road, Bangbu of Anhui Province 233004, People's Republic of China.
Du
Wen-Hua
WH
Liu
Xiao-Yan
XY
Fan
Yan-Ping
YP
Hu
Xiao-Lei
XL
Zhou
Hai-Yan
HY
Xu
Huan-Bai
HB
Zhang
Xiao-Mei
XM
Xiang
Ping
P
Chen
Feng-Ling
FL
D052438:Adipocytes, White / Q000187:drug effects* / Q000378:metabolism*; D052242:Adiponectin / Q000097:blood* / Q000235:genetics*; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D001947:Breeding; D004041:Dietary Fats / Q000009:adverse effects; D005786:Gene Expression Regulation / Q000187:drug effects*; D006854:Hydrocortisone / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D009765:Obesity / Q000097:blood / Q000209:etiology / Q000235:genetics / Q000503:physiopathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats
D052242:Adiponectin; D004041:Dietary Fats; D012333:RNA, Messenger; C007133:hydrocortisone hemisuccinate; D006854:Hydrocortisone