Insulin sensitization with a peroxisome proliferator-activated receptor γ agonist prevents adrenocortical lipid infiltration and secretory changes induced by a high-sucrose diet.
It has been hypothesized that deviations in glucocorticoid secretion and/or action may contribute to somatic and biochemical changes observed in patients with and animal models of insulin resistance (IR). In this study, we analyzed changes in rat adrenocortical function and morphology associated with the development of IR, generated in male adult rats by the addition of 30% sucrose to the drinking water. Caloric intake, body and adipose tissue weights, and biochemical parameters associated with IR were determined. Expression levels of Star, Cyp11A1, Mc2r, Pparγ (Pparg), and Cd36 were evaluated by real-time PCR, histochemical analysis of the adrenal cortex was performed using Masson's trichrome and Sudan III staining, and corticosterone levels were measured by RIA. After 7 weeks of sucrose administration, higher serum glucose, insulin, and triglyceride levels and an altered glycemic response to an i.p. insulin test were detected. Adrenal glands showed a neutral lipid infiltration. An increase in Star, Cyp11A1, Mc2r, Pparg and Cd36 and a decrease in Mc2r levels were also found. Furthermore, sucrose-treated animals exhibited higher basal corticosterone levels and a blunted response to ACTH injection. Noteworthy, the adrenocortical (functional and histological) abnormalities were prevented in sucrose-treated rats by the simultaneous administration of an insulin-sensitizing PPARγ agonist. In conclusion, sucrose-induced IR affects adrenocortical morphology and function possibly via the generation of adipokines or lipid metabolites within the adrenal gland. These abnormalities are prevented by the administration of a PPARγ agonist by mechanisms involving both extra- and intra-adrenal effects.
Department of Human Biochemistry, School of Medicine, University of Buenos Aires, CEFYBO, CONICET, Paraguay 2155, Buenos Aires C1121ABG, Argentina.
Camila
C
Martinez Calejman
Juan M
JM
Di Gruccio
María E
ME
Mercau
Esteban M
EM
Repetto
Francisco
F
Astort
Rocío
R
Sanchez
Matías
M
Pandolfi
Gabriela
G
Berg
Laura
L
Schreier
Pablo
P
Arias
Cora B
CB
Cymeryng
D000302:Adrenal Cortex / Q000378:metabolism* / Q000473:pathology; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D003345:Corticosterone / Q000097:blood; D019422:Dietary Sucrose / Q000494:pharmacology*; D002149:Energy Intake / Q000187:drug effects / Q000502:physiology; D006728:Hormones / Q000494:pharmacology; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007328:Insulin / Q000097:blood / Q000494:pharmacology; D007333:Insulin Resistance / Q000502:physiology*; D052439:Lipid Metabolism Disorders / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D047495:PPAR gamma / Q000819:agonists* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000494:pharmacology*; D014280:Triglycerides / Q000097:blood
D019422:Dietary Sucrose; D006728:Hormones; D007004:Hypoglycemic Agents; D007328:Insulin; D047495:PPAR gamma; D045162:Thiazolidinediones; D014280:Triglycerides; D000077154:Rosiglitazone; D000324:Adrenocorticotropic Hormone; D003345:Corticosterone