RESUMEN
The mammary gland (MG) and female prostate are plastic reproductive organs which are highly responsive to hormones. Thus, endocrine disruptors, such as bisphenol A (BPA) and exogenous estrogens, negatively affect glandular homeostasis. In addition to previously described alterations, changes in inflammatory markers expression also trigger the development of a microenvironment that contributes to tumor progression. The current work aimed to evaluate the inflammatory responses of the MG and prostate gland to BPA (50 µg/kg) and 17-ß estradiol (35 µg/kg) exposure during the perinatal window of susceptibility. The results showed that at 6 months of age there was an increase in the number of phospho-STAT3 (P-STAT3) positive cells in the female prostate from animals perinatally exposed to 50 µg/kg BPA daily. In addition, the number of macrophages increased in these animals in comparison with nonexposed animals, as shown by the F4/80 marker. Despite an increase in the incidence of lobuloalveolar and intraductal hyperplasia, the MG did not show any difference in the expression of the four inflammatory markers evaluated: tumor necrosis factor-α, COX-2, P-STAT3, and F4/80. Analysis of both glands from the same animal led to the conclusion that exposure to endocrine disruptors during the perinatal window of susceptibility leads to different inflammatory responses in different reproductive organs. As the prostate is more susceptible to these inflammatory mechanisms, it is reasonable to affirm that possible neoplastic alterations in this organ are related to changes in the inflammatory pattern of the stroma, a characteristic that is not evident in the MG.
Asunto(s)
Disruptores Endocrinos/farmacología , Glándulas Endocrinas/efectos de los fármacos , Glándulas Mamarias Animales/metabolismo , Animales , Animales Recién Nacidos/metabolismo , Compuestos de Bencidrilo/farmacología , Disruptores Endocrinos/metabolismo , Glándulas Endocrinas/metabolismo , Estradiol/farmacología , Femenino , Genitales Femeninos/efectos de los fármacos , Genitales Femeninos/metabolismo , Gerbillinae , Humanos , Inflamación/metabolismo , Glándulas Mamarias Animales/efectos de los fármacos , Fenoles/farmacología , Embarazo , Efectos Tardíos de la Exposición Prenatal/metabolismo , Factor de Transcripción STAT3/efectos de los fármacos , Factor de Transcripción STAT3/metabolismo , Esteroides/farmacologíaRESUMEN
The endocrine disruptive effects caused by bisphenol A (BPA) are well known. Despite this, to date, evaluation of its long term effects is limited, meaning that there is still much to be unveiled in terms of alterations caused by perinatal exposure to BPA. Our aim was to determine if perinatal exposure to two different doses of BPA causes long term morphological and molecular alteration effects in the mammary gland (MG). We evaluated MG from Mongolian gerbil offspring exposed perinatally (during gestation and lactation) to 50 or 5000 µg/kg/day BPA. At 90 days of age the animals were subjected to a single dose of N-nitroso-N-methylurea in order to mimic a carcinogenic environment. At 6 months of age, animals in estrous were euthanized for morphological evaluation of the MGs. The MG architecture presented considerable changes in terms of detached epithelial cells, inflammation, glandular hyperplasia, and collagen fiber deposition. Furthermore, a higher index of epithelial cell proliferation was detected in comparison to the intact control group. In addition, we verified a higher molecular expression of EZH2 in the vehicle treated group, indicating that corn oil applied alone can alter the expression of this epigenetic biomarker. In conclusion, BPA perinatal exposure promotes significant changes in glandular cytoarchitecture and increases glandular epithelium proliferation rate, leading to the retention of stem-like properties. This event could compromise the fate and differentiation potential of mammary epithelium.
Asunto(s)
Envejecimiento/patología , Compuestos de Bencidrilo/toxicidad , Glándulas Mamarias Animales/patología , Fenoles/toxicidad , Efectos Tardíos de la Exposición Prenatal/patología , Actinas/metabolismo , Animales , Proliferación Celular , Colágeno/metabolismo , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Femenino , Gerbillinae , Histonas/metabolismo , Glándulas Mamarias Animales/efectos de los fármacos , EmbarazoRESUMEN
Hormonal regulation controls mammary gland (MG) development. Therefore some hormone-related factors can disrupt the early phases of MGs development, making the gland more susceptible to long term modifications in its response to circulating hormones. Endocrine disruptors, such as bisphenol A (BPA), are able to cause alterations in hormone receptor expression, leading to changes in the cell proliferation index, which may expose the tissue to neoplastic alterations. Thus, we evaluated the variations in hormone receptor expression in the MG of 6-month old Mongolian gerbils exposed to BPA and 17ß estradiol during the perinatal period. Receptors for estrogen alpha (ERα), beta (ERß), progesterone (PGR), prolactin (PRL-R), and co-localization of connexin 43 (Cx43) and ERα in gerbils were analyzed, and serum concentrations of estradiol and progesterone were assessed. No alterations in body, liver, and ovary-uterus complex weights were observed. However, there was an increase in epithelial ERα expression in the 17ß estradiol (E2) group and in PGR in the BPA group. Although immunohistochemistry did not show alterations in ERß expression, western blotting revealed a decrease in this protein in the BPA group. PRL-R was more present in epithelial cells in the vehicle control (VC), E2, and BPA groups in comparison to the intact control group. Cx43 was more frequent in E2 and BPA groups, suggesting a protective response from the gland against possible malignancy. Serum concentration of estradiol reduced in VC, E2, and BPA groups, confirming that alterations also impacts steroid levels. Consequently, perinatal exposure to BPA and the reference endogenous estrogen, 17ß estradiol, are able to increase the tendency of endocrine disruption in MG in a long term manner, since repercussions are observed even 6 months after exposure.
Asunto(s)
Compuestos de Bencidrilo/toxicidad , Disruptores Endocrinos/toxicidad , Estradiol/toxicidad , Glándulas Mamarias Animales/efectos de los fármacos , Fenoles/toxicidad , Efectos Tardíos de la Exposición Prenatal/metabolismo , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismo , Animales , Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/metabolismo , Femenino , Gerbillinae , Glándulas Mamarias Animales/embriología , Glándulas Mamarias Animales/metabolismo , Embarazo , Efectos Tardíos de la Exposición Prenatal/inducido químicamenteRESUMEN
Ovarian tissue cryopreservation is a promising technique for fertility maintenance. The aim of this study was to compare the morphology of domestic cat ovarian follicles after tissue cryopreservation with ethylene glycol (EG) and dimethyl sulfoxide (Me2SO). Ovaries from healthy adult cats undergoing elective ovariohysterectomy were used. Eight fragments were obtained from each pair of ovaries: two were used as fresh controls; three were submitted to fresh perfusion toxicity test and perfused with M199, 10% fetal calf serum and 0.4% sucrose containing Me2SO 1.5â¯M, EG 1.5â¯M or Me2SO 0.75 M + EG 0.75 M; and the remaining three fragments were perfused as described and submitted to slow freezing. After 45 days of cryopreservation, the samples were thawed, fixed and processed for light and transmission electron microscopy (TEM). The percentages of morphologically normal follicles identified by light microscopy were higher in the control group (94.45%) in comparison to the frozen groups (80.56% with EG, 78.7% with Me2SO and 75.87% with EG + Me2SO). The fresh perfused tissue showed no statistical difference compared to control or frozen samples. The TEM analysis showed less damage in the ultrastructure of follicles from the Me2SO group in comparison with the EG and Me2SO + EG groups. According to the morphological analysis, 1.5 M Me2SO is the best cryoprotectant for cryopreservation of domestic cat ovarian tissue regarding the morphology of preantral follicles after thawing. Further studies regarding the viability of these follicles should be performed.
Asunto(s)
Criopreservación/veterinaria , Crioprotectores/farmacología , Dimetilsulfóxido/farmacología , Glicol de Etileno/farmacología , Folículo Ovárico/ultraestructura , Animales , Gatos , Femenino , Congelación , Microscopía Electrónica de TransmisiónRESUMEN
The female prostate is associated with the urogenital system and presents homology in morphological terms with the male prostate. Due to its responsiveness to endogenous hormones, this gland is under a constant risk of developing prostatic pathologies and neoplasia when exposed to certain exogenous compounds. Bisphenol A (BPA) is an endocrine disruptor found in different plastic and resin products. Studies have emphasized the effects of perinatal exposure to this compound on different hormone-responsive organs. However, there have been few studies highlighting the influence on female prostate morphology of perinatal exposure to BPA. The objective of this study was to describe the histopathological alterations caused by perinatal exposure to BPA (50 µg/kg) and 17-ß estradiol (E2) (35 µg/kg) in the prostate of adult female gerbils. The results showed that E2 and BPA induced proliferative lesions in the female prostate and acted along similar pathways by modulating steroid receptors in the epithelium. BPA was also found to be a pro-inflammatory and pro-angiogenic agent. The impacts of both agents were marked in the prostatic stroma. An increase in the thickness of the smooth muscle layer and a decrease in AR expression were observed, but no alterations in the expression of ERα and ERß, leading to estrogenic sensitivity of the prostate. However, a peculiar response of the female prostate was to diminish the collagen frequency under BPA exposure correlated to smooth muscle layer. These data therefore indicate the development of features related to estrogenic and non-estrogenic tissue repercussions by BPA perinatally exposure in gerbil female prostate.
Asunto(s)
Disruptores Endocrinos , Próstata , Animales , Embarazo , Masculino , Femenino , Gerbillinae , Fenoles/toxicidad , Compuestos de Bencidrilo/toxicidad , Disruptores Endocrinos/metabolismoRESUMEN
Ultimately, the Mongolian gerbils (Meriones unguiculatus) have acquired a relevant role in biological and biomedical experiments alongside other rodents. The use of gerbils in research has been mainly oriented to physiological and pharmacological studies, with special attention to nervous, digestive, and auditory systems as well as microbiology and parasitology. Ultimately, gerbils have also been applied for studying carcinogenesis in different organs and systems, since these animals show a natural propensity to develop spontaneous proliferative lesions, especially in steroid-responsive organs. This characteristic shed light on the reproductive aspects of this rodent model regarding morphological features in male and female individuals. This review of literature summarizes the significance of this model as an alternative to the use of inbred mice and rats in reproductive experimental research, highlighting recent findings. Gerbils have contributed to the expansion of knowledge in prostate biology in male and female individuals, providing studies related to prostatic morphogenesis and neoplasia. In the testes, spermiogenesis occurs in 15 steps, differently from other experimental models. Also, the complete maturation of the testis-epididymal complex occurs between the second and third months. Mammary gland alterations related to the estrous cycle and pregnancy were described, as well as its modulation under endogenous and exogenous estrogenic compounds. The ovaries frequently present ovarian cysts. Furthermore, this organ shows predominantly interstitial steroidogenic glands in the stroma, especially at aging. Adrenal gland shows a large size compared to other animals, presenting three distinct zones with a remarkable role in steroidogenesis.
Asunto(s)
Estrógenos , Reproducción , Embarazo , Masculino , Femenino , Ratas , Ratones , Animales , Gerbillinae/fisiología , Estrógenos/fisiología , Próstata/fisiología , BiologíaRESUMEN
Condyloma acuminata (CA) is a benign proliferative disease mainly affecting in non-keratinized epithelia. Most cases of CA are caused by low-risk human papillomavirus (HPV), mainly HPV 6 and 11. The aim of the current study was to highlight the candidate genes and pathways associated with immune alterations in individuals who did not spontaneously eliminate the virus and, thus, develop genital warts. Paraffin-embedded condyloma samples (n = 56) were analyzed by immunohistochemistry using antibodies against CD1a, FOXP3, CD3, CD4, CD8, and IFN-γ. The immunomarkers were chosen based on the evaluation of the innate and adaptive immune pathways using qPCR analysis of 92 immune-related genes, applying a TaqMan Array Immune Response assay in HPV 6 or HPV 11 positive samples (n = 27). Gene expression analysis revealed 31 differentially expressed genes in CA lesions. Gene expression validation revealed upregulation of GZMB, IFNG, IL12B, and IL8 and downregulation of NFATC4 and IL7 in CA samples. Immunohistochemical analysis showed increased FOXP3, IFN-γ, CD1a, and CD4 expression in CA than in the control tissue samples. In contrast, CD3 and CD8 expression was decreased in CA lesion samples. Increased levels of pro-inflammatory cytokines in HPV-positive patients compared with HPV-negative patients seem to reflect the elevated immunogenicity of HPV-positive CA lesions. Host defense against HPV begins during the early stages of the innate immune response and is followed by activation of T lymphocytes, which are mainly represented by CD4+ and regulatory T cells. The low CD8+ T cell count in CA may contribute to this recurrent behavior. Additional studies are needed to elucidate the mechanism of host defense against HPV infection in CA.
Asunto(s)
Condiloma Acuminado , Infecciones por Papillomavirus , Humanos , Infecciones por Papillomavirus/genética , Condiloma Acuminado/genética , Condiloma Acuminado/patología , Citocinas , Inmunidad , Factores de Transcripción Forkhead/genética , Papillomaviridae/genéticaRESUMEN
In the mammary gland (MG), the developmental window for gestational/lactational differentiation and growth is highly vulnerable to hormonal disruption. Here we describe that the MG involution process in female gerbil mothers is delayed by bisphenol A (BPA) exposure during gestation and lactation. The process is directly influenced by changes in expression of extracellular matrix proteases MMP-2, MMP-9, and FAP, and the incidence of collagen and elastin is reduced after 7 and 14 days of weaning. A pro-inflammatory environment in the late involution process was confirmed by higher expression of TNF-α, COX-2 and phospho-STAT3 n the MG stroma, allied to increases in the incidence of macrophages and mast cells. These aspects impacted the proliferative pattern of epithelial cells, which decreased on the 14th post-weaning day. These data confirm that the milk production window of susceptibility is vulnerable to the impact of BPA, which promotes a suggestive pro-tumoral microenvironment during mammary involution.
Asunto(s)
Compuestos de Bencidrilo/toxicidad , Disruptores Endocrinos/toxicidad , Lactancia , Glándulas Mamarias Animales/efectos de los fármacos , Fenoles/toxicidad , Animales , Células Epiteliales/efectos de los fármacos , Femenino , Gerbillinae , Inflamación , Glándulas Mamarias Animales/crecimiento & desarrollo , Metaloproteinasas de la Matriz/metabolismo , Embarazo , Células del Estroma/metabolismo , DesteteRESUMEN
Mammary gland (MG) undergoes critical points of structural changes throughout a woman's life. During the perinatal and pubertal stages, MG develops through growth and differentiation to establish a pre-mature feature. If pregnancy and lactation occur, the epithelial compartment branches and differentiates to create a specialized structure for milk secretion and nurturing of the newborn. However, the ultimate MG modification consists of a regression process aiming to reestablish the smaller and less energy demanding structure until another production cycle happens. The unraveling of these fascinating physiologic cycles has helped the scientific community elucidate aspects of molecular regulation of proliferative and apoptotic events and remodeling of the stromal compartment. However, greater understanding of the hormonal pathways involved in MG developmental stages led to concern that endocrine disruptors such as bisphenol A (BPA), may influence these specific development/involution stages, called "windows of susceptibility". Since it is used in the manufacture of polycarbonate plastics and epoxy resins, BPA is a ubiquitous chemical present in human everyday life, exerting an estrogenic effect. Thus, descriptions of its deleterious effects on the MG, especially in terms of serum hormone concentrations, hormonal receptor expression, molecular pathways, and epigenetic alterations, have been widely published. Therefore, allied to a didactic description of the main physiological mechanisms involved in different critical points of MG development, the current review provides a summary of key mechanisms by which the endocrine disruptor BPA impacts MG homeostasis at different windows of susceptibility, causing short- and long-term effects.
Asunto(s)
Compuestos de Bencidrilo/toxicidad , Disruptores Endocrinos/toxicidad , Glándulas Mamarias Humanas/efectos de los fármacos , Fenoles/toxicidad , Animales , Femenino , Homeostasis , Humanos , Glándulas Mamarias Humanas/crecimiento & desarrolloRESUMEN
Breast cancer is the most common neoplasm among women but thanks to innovative therapies, patients' prognosis has considerably improved. In this aspect, nanotechnology has been applied for cancer therapy aiming to reduce its usual side effects. In this study we aimed to evaluate the effects of nanoemulsions containing photosensitizer and chemotherapeutic agents associated with photodynamic therapy in a breast cancer in vivo model. Our results showed that synergistic treatments in which chloroaluminum phthalocyanine (NE-Pc) administered together with Doxorubicin (Dox) in the presence of laser irradiation (NE-PcDoxo + PDT) led to a reduction of 4 T1 induced breast cancer in mice, decline of tumor VEGF expression, increase in Caspase-3 expression, tissue necrosis and massive decrease in proliferative cells, as shown by Ki67 immunostaining. Furthermore, this associated treatment induced overexpression of apoptotic genes ABL1, CD70, CRADD, FASL, and NME5 and a reduction in expression of anticancer drug target genes CDK2, ERBB2, FIGF, IGF2, PARP4 and PGR. These results validate this treatment as a promising alternative to improve the currently applied anticancer strategies.
Asunto(s)
Antineoplásicos/química , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/radioterapia , Doxorrubicina/química , Indoles/química , Nanocápsulas/química , Compuestos Organometálicos/química , Fármacos Fotosensibilizantes/química , Animales , Antineoplásicos/farmacología , Caspasa 3/genética , Caspasa 3/metabolismo , Quinasa 2 Dependiente de la Ciclina/genética , Quinasa 2 Dependiente de la Ciclina/metabolismo , Doxorrubicina/farmacología , Descubrimiento de Drogas , Quimioterapia Combinada , Emulsiones/química , Femenino , Humanos , Indoles/farmacología , Ratones , Ratones Endogámicos BALB C , Neoplasias Experimentales , Compuestos Organometálicos/farmacología , Fotoquimioterapia , Fármacos Fotosensibilizantes/farmacología , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
AIMS: Hormone receptors are the main markers applied for prognosis of breast cancer subtypes. Among modulators, exogenous chemical agents known as endocrine disruptors interact with certain receptors, triggering molecular pathways or increasing their expression. Bisphenol A (BPA), a xenoestrogen, interacts with several hormone receptors. Thus, our aim was to characterize the hormone receptor status in the mammary gland (MG) of aged female Mongolian gerbils exposed to BPA in pregnancy and lactation. METHODS: We evaluated the expression of receptors for estrogens (ERα and ERß), progesterone (PR), prolactin (PRL-R), HER2/ErbB2, and androgen (AR) in normal and hyperplastic mammary tissue and in carcinomas developed after BPA exposure. KEY FINDINGS: BPA-exposed MG presented increased ERα, whereas ERß, PR, and PRL-R showed lower expression. AR and HER2/ErbB2 showed similar expression in normal and hyperplastic tissue from control, vehicle, and BPA groups. Both receptors were found in cytoplasm and nucleus in BPA-induced carcinoma. We demonstrate the presence of EZH2 expression, an epigenetic and epithelial-mesenchymal transition (EMT) marker, with a high H-score in BPA-exposed MG, which was associated with poor prognosis of cancer. Co-localization of ERα and EZH2 was present in normal and carcinoma features, corroborating the installation of ERα-positive mammary cancer associated with the EMT process. Enhanced EZH2 in BPA-exposed mammary tissue could decrease ERß expression and promote tumorigenesis progress through HER2/ErbB2. SIGNIFICANCE: The present study proposes the Mongolian gerbil as an experimental model for mammary carcinogenesis studies, based on BPA disruption that triggers a phenotype of increased ERα/HER2 positivity and depletion of ERß/PR expression.
Asunto(s)
Envejecimiento , Compuestos de Bencidrilo/efectos adversos , Neoplasias de la Mama/inducido químicamente , Carcinogénesis/inducido químicamente , Disruptores Endocrinos/efectos adversos , Glándulas Mamarias Animales/efectos de los fármacos , Exposición Materna , Fenoles/efectos adversos , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismo , Animales , Neoplasias de la Mama/metabolismo , Carcinogénesis/metabolismo , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Femenino , Gerbillinae , Glándulas Mamarias Animales/metabolismo , Neoplasias Mamarias Experimentales/inducido químicamente , Neoplasias Mamarias Experimentales/metabolismoRESUMEN
While still considered an experimental procedure in most countries, ovarian tissue cryopreservation and transplantation has been increasingly applied worldwide to restore fertility in patients with malignant and non-malignant pathologies with risk of premature ovarian insufficiency. It has yielded more than 130 live births up to now and almost all transplanted patients recovered their ovarian function. This study summarizes ovarian tissue cryopreservation and transplantation indications, procedures, their efficacy and main results and proposes different strategies to improve this strategy. Although the main focus of this study is on ovarian tissue cryopreservation and transplantation as a strategy to restore fertility, we believe that it is also important to discuss other applications for this approach.
Asunto(s)
Criopreservación , Preservación de la Fertilidad/métodos , Infertilidad/terapia , Ovario , Criopreservación/métodos , Femenino , Humanos , Ovario/trasplante , Embarazo , Insuficiencia Ovárica Primaria/terapia , Reoperación , Trasplante AutólogoRESUMEN
The advantage of stepped vitrification (SV) is avoiding ice crystal nucleation, while decreasing the toxic effects of high cryoprotectant concentrations. We aimed to test this method for human ovarian tissue cryopreservation. Ovarian cortex was taken from 7 fertile adult women. Samples were subjected to an SV protocol performed in an automatic freezer, which allowed sample transfer to ever higher concentrations of dimethyl sulfoxide (DMSO) as the temperature was reduced. Histological evaluation of the vitrified-warmed tissue showed large numbers of degenerated follicles after 24 hours of in vitro culture. We therefore evaluated DMSO perfusion rates by X-ray computed tomography, ice crystal formation by freeze-substitution, and cell toxicity by transmission electron microscopy, seeking possible reasons why follicles degenerated. Although cryoprotectant perfusion was considered normal and no ice crystals were formed in the tissue, ultrastructural analysis detected typical signs of DMSO toxicity, such as mitochondria degeneration, alterations in chromatin condensation, cell vacuolization and extracellular matrix swelling in both stromal and follicular cells. The findings indicated that the method failed to preserve follicles due to the high concentrations of DMSO used. However, adaptations can be made to avoid toxicity to follicles caused by elevated levels of cryoprotectants.
Asunto(s)
Criopreservación/métodos , Crioprotectores/farmacología , Dimetilsulfóxido/farmacología , Folículo Ovárico/efectos de los fármacos , Vitrificación , Adulto , Femenino , HumanosRESUMEN
4-vinilcyclohexene diepoxide (4-VCD) causes premature ovarian failure and may result in estrogen deficiency, characterizing the transition to estropause in rodents (equivalent to menopause in women). Estropause/menopause is associated with metabolic derangements such as glucose intolerance and insulin resistance. Glucocorticoids (GCs) are known to exert diabetogenic effects. Thus, we aimed to investigate whether rats with premature ovarian failure are more prone to the diabetogenic effects of GC. For this, immature female rats received daily injections of 4-VCD [160mg/kg body weight (b.w.), intraperitoneally (i.p.)] for 15 consecutive days, whereas control rats received vehicle. After 168days of the completion of 4-VCD administration, rats were divided into 4 groups: CTL-received daily injections of saline (1mL/kg, b.w., i.p.) for 5days; DEX-received daily injections of dexamethasone (1mg/kg, b.w., i.p.) for 5days; VCD-treated as CTL group; VCD+DEX-treated as DEX group. Experiments and euthanasia occurred one day after the last dexamethasone injection. 4-VCD-treated rats exhibited ovary hypotrophy and reduced number of preantral follicles (p<0.05). Premature ovarian failure had no impact on the body weight gain or food intake, but both were reduced by the effects of dexamethasone. The increase in blood glucose, plasma insulin and triacylglycerol levels as well as the reduction in insulin sensitivity caused by dexamethasone treatment was not exacerbated in the VCD+DEX group of rats. Premature ovarian failure did change neither the hepatic content of glycogen and triacylglycerol nor the glycerol release from perigonadal adipose tissue. Glucose intolerance was observed in the VCD group after an ipGTT (p<0.05), but not after an oral glucose challenge. Glucose intolerance and compensatory pancreatic ß-cell mass caused by GC were not modified by ovarian failure in the VCD+DEX group. We conclude that reduced ovarian function has no major implications on the diabetogenic effects promoted by GC treatment, indicating that other factors related to aging may make rats more vulnerable to GC side effects on glucose metabolism.