17β-Estradiol attenuates diet-induced insulin resistance and glucose intolerance through up-regulation of caveolin-3.
BACKGROUND
Although estrogen contributes to glucose homeostasis, its mechanisms remain unclear.


OBJECTIVE
To investigate the role of caveolin-3 in estrogen's effects on glucose metabolism.


METHODS
Ovariectomized (OVX) and sham-operated rats, fed with normal chow diet (NCD) or high-calorie diet (HCD), received 17β-estradiol (E(2)) or placebo. Fasting plasma glucose (FPG) was detected and HOMA-IR was calculated. Primary cultured skeletal muscle cells were treated with E(2), in the presence or absence of β-methyl-cyclodextrin and tamoxifen. Glucose consumption and transportation and expression of caveolin-3 were examined.


RESULTS
In NCD-fed rats, OVX or E(2) had no effects on FPG or HOMA-IR. In HCD-fed rats, OVX led to the increase of FPG and HOMA-IR, which was attenuated by E(2). In cultured cells, E(2) improved glucose consumption and transportation and enhanced caveolin-3 expression, which were blocked by β-methyl-cyclodextrin and tamoxifen.


CONCLUSIONS
Caveolin-3 plays an important role in the mechanism by which E(2) attenuates diet-induced glucose intolerance.
Mu
P
P
Department of Endocrinology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510630, China.
Tan
Z
Z
Cui
Y
Y
Liu
H
H
Xu
X
X
Huang
Q
Q
Zeng
L
L
Wang
T
T
D000818:Animals; D015153:Blotting, Western; D051244:Caveolin 3 / Q000378:metabolism*; D004958:Estradiol / Q000502:physiology*; D004965:Estrogen Antagonists / Q000494:pharmacology; D005260:Female; D006706:Homeostasis / Q000502:physiology; D007333:Insulin Resistance / Q000502:physiology*; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013629:Tamoxifen / Q000494:pharmacology; D015854:Up-Regulation / Q000502:physiology; D047392:beta-Cyclodextrins / Q000494:pharmacology
D051244:Caveolin 3; D004965:Estrogen Antagonists; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D013629:Tamoxifen; D004958:Estradiol