当前位置： SCI文献检索 > BRITISH JOURNAL OF PHARMACOLOGY期刊下所有文献 > Chronic mTOR inhibition by rapamycin induces muscle insulin resistance despite weight loss in rats.

Chronic mTOR inhibition by rapamycin induces muscle insulin resistance despite weight loss in rats.

Abstract：

BACKGROUND AND PURPOSE:mTOR inhibitors are currently used as immunosuppressants in transplanted patients and as promising anti-cancer agents. However, new-onset diabetes is a frequent complication occurring in patients treated with mTOR inhibitors such as rapamycin (Sirolimus). Here, we investigated the mechanisms associated with the diabetogenic effects of chronic Sirolimus administration in rats and in in vitro cell cultures. EXPERIMENTAL APPROACH:Sirolimus was administered to rats fed either a standard or high-fat diet for 21 days. Metabolic parameters were measured in vivo and in ex vivo tissues. Insulin sensitivity was assessed by glucose tolerance tests and euglycaemic hyperinsulinaemic clamps. Rapamycin effects on glucose metabolism and insulin signalling were further evaluated in cultured myotubes. KEY RESULTS:Sirolimus induced a decrease in food intake and concomitant weight loss. It also induced specific fat mass loss that was independent of changes in food intake. Despite these beneficial effects, Sirolimus-treated rats were glucose intolerant, hyperinsulinaemic and hyperglycaemic, but not hyperlipidaemic. The euglycaemic hyperinsulinaemic clamp measurements showed skeletal muscle is a major site of Sirolimus-induced insulin resistance. At the molecular level, long-term Sirolimus administration attenuated glucose uptake and metabolism in skeletal muscle by preventing full insulin-induced Akt activation and altering the expression and translocation of glucose transporters to the plasma membrane. In rats fed a high-fat diet, these metabolic defects were exacerbated, although Sirolimus-treated animals were protected from diet-induced obesity. CONCLUSIONS AND IMPLICATIONS:Taken together, our data demonstrate that the diabetogenic effect of chronic rapamycin administration is due to an impaired insulin action on glucose metabolism in skeletal muscles.

journal_name

Br J Pharmacol

journal_title

British journal of pharmacology

authors

Deblon N,Bourgoin L,Veyrat-Durebex C,Peyrou M,Vinciguerra M,Caillon A,Maeder C,Fournier M,Montet X,Rohner-Jeanrenaud F,Foti M

doi

10.1111/j.1476-5381.2011.01716.x

subject

Has Abstract

pub_date

2012-04-01 00:00:00

pages

2325-40

issue

eissn

0007-1188

issn

1476-5381

journal_volume

165

pub_type

杂志文章

在线工具

Chronic mTOR inhibition by rapamycin induces muscle insulin resistance despite weight loss in rats.