Morphofunctional Alterations in Endocrine Pancreas of Short- and Long-term Dexamethasone-treated Rats

dc.contributorUniversidade Estadual Paulista (UNESP)
dc.creatorRafacho, A.
dc.creatorAbrantes, J. L. F.
dc.creatorRibeiro, D. L.
dc.creatorPaula, F. M.
dc.creatorPinto, M. E.
dc.creatorBoschero, A. C.
dc.creatorBosqueiro, José Roberto
dc.date2014-05-20T14:00:48Z
dc.date2016-10-25T17:08:11Z
dc.date2014-05-20T14:00:48Z
dc.date2016-10-25T17:08:11Z
dc.date2011-04-01
dc.date.accessioned2017-04-05T21:23:50Z
dc.date.available2017-04-05T21:23:50Z
dc.identifierHormone and Metabolic Research. Stuttgart: Georg Thieme Verlag Kg, v. 43, n. 4, p. 275-281, 2011.
dc.identifier0018-5043
dc.identifierhttp://hdl.handle.net/11449/21474
dc.identifierhttp://acervodigital.unesp.br/handle/11449/21474
dc.identifier10.1055/s-0030-1269896
dc.identifierWOS:000288984100009
dc.identifierhttp://dx.doi.org/10.1055/s-0030-1269896
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/867035
dc.descriptionLong-term dexamethasone therapy may induce peripheral insulin resistance (IR), which in turn elicits increased beta-cell function and proliferation. However, whether such adaptive compensations occur during short-term treatment with dexamethasone is unclear. Here, we compared morphofunctional parameters in endocrine pancreas after short- and long-term dexamethasone administration. Groups of rats received daily i.p. injection of 1 mg/kg b.w. dexamethasone for 1 (DEX-1), 3 (DEX-3), or 5 consecutive days (DEX-5), whilst control rats were saline-treated (CTL). Despite the absence of apparent IR in DEX-1 rats, this group exhibited increased circulating insulin levels and glucose-stimulated insulin secretion (GSIS), compared to the CTL group (p < 0.05). Evident IR as well as marked hyperinsulinemia and GSIS, as judged by the static and dynamic insulin secretion values, were observed in DEX-3 and DEX-5 rats (p < 0.05). GSIS in islets cultured with 1 mu M dexamethasone was lower compared to the control (p < 0.05). Marked increases in beta-cell proliferation were observed in DEX-3 and DEX-5 rats, compared to CTL and DEX-1 rats (p < 0.05). The alterations observed in DEX-3 rats were more pronounced in DEX-5 rats, which also exhibited a higher content of islet Cdk4 and Cd2 proteins, compared to the CTL group (p < 0.05). We conclude that short-term dexamethasone treatment (DEX-1) induces an increase in beta-cell function that does not require the presence of discernible IR. As the treatment continues, the IR develops rapidly, and increased insulin secretion as well as beta-cell hyperplasia is demanded for the appropriate maintenance of glucose homeostasis.
dc.descriptionFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.languageeng
dc.publisherGeorg Thieme Verlag Kg
dc.relationHormone and Metabolic Research
dc.rightsinfo:eu-repo/semantics/closedAccess
dc.subjectbeta-cell proliferation
dc.subjectdexamethasone
dc.subjectGlucocorticoid
dc.subjectinsulin secretion
dc.subjectinsulin resistance
dc.subjectshort- and long-term treatment
dc.titleMorphofunctional Alterations in Endocrine Pancreas of Short- and Long-term Dexamethasone-treated Rats
dc.typeOtro


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