Leptin in embryos from control and diabetic rats during organogenesis: a modulator of nitric oxide production and lipid homeostasis.
· White V,
· Gonzalez E,
· Pustovrh C,
· Capobianco E,
· Martinez N,
· Do Porto DF,
· Higa R,
· Jawerbaum A.
Laboratory of Reproduction and Metabolism, CEFYBO-CONICET, School of Medicine, University of Buenos Aires, Paraguay 2155 (1121ABG) Buenos Aires, Argentina.
BACKGROUND: Leptin is involved in many metabolic and reproductive events and its levels are altered by the diabetic pathology. In this study, leptin concentrations and leptin effects on both nitric oxide (NO) and lipid concentrations were investigated in embryos from control and diabetic rats. METHODS: Diabetes was induced by neonatal streptozotocin administration (90 mg/kg). Embryos from control and diabetic rats were obtained on days 10.5 and 13.5 of gestation, corresponding to early organogenesis and post-placentation periods respectively. Leptin was analysed by enzyme immunoanalysis and immunohistochemistry. Nitrates and nitrites were assessed as an index of NO production. Lipid concentrations were analysed by thin layer chromatography. RESULTS: Leptin concentrations were decreased in embryos obtained from diabetic rats on days 10.5 and 13.5 of gestation when compared to controls. NO concentrations, elevated in diabetic embryopathy, were diminished in the presence of leptin in the embryos obtained from control and diabetic animals both during early organogenesis and after placentation. Leptin additions reduced phospholipid, cholesterol and cholesteryl ester concentrations in embryos obtained from diabetic rats during early organogenesis, although no leptin effects on lipid concentrations were observed in control embryos at this developmental stage. In embryos obtained on day 13.5 of gestation leptin additions reduced cholesteryl ester concentrations in controls, and diminished cholesteryl ester, triglycerides and phospholipids in embryos from diabetic rats. CONCLUSIONS: We demonstrated that leptin plays a role in the regulation of NO concentrations and lipid homeostasis during embryo organogenesis and that the diabetic environment causes a reduction of leptin concentrations in rat embryos. Copyright (c) 2007 John Wiley & Sons, Ltd.
PMID: 17506117 [PubMed - as supplied by publisher]
TRADUCCION.
Leptina esta involucrada en muchos eventos reproductivos y metabólicos y sus niveles estan alterados por la diabetes.
In este studio las concentraciones de leptina y sus efectos sobre la acumulación de oxido nitroso y la concentracion de lípidos fueron investigadas en embriones de controles y ratas diabéticas por ausencia de insulina. Embriones de ratas control y diabéticas fueron obtenidos en los días 10,5 y y 13,5 de gestacion correspondientes a los períodos de la organogénesis precoz y post placentación respectivamente. RESULTADOS. Las concentraciones de leptina fueron reducidas en embriones de ratas diabéticas en ambos períodos de gestación respecto de ratas normales. Los niveles de Oxido nitroso (NO) elevados en la embriopatía diabética estuvieron disminuidos en presencia de leptina en las ratas normales en ambos periodos de la gestación. La adición de leptina redujo los fosfolípidos cholesterol y esters de cholesterol en los embriones de ratas diabéticas durante la organogenesispero no se manifestaron efectos sobre ellos en embriones de rats control en este período de la gestación. En el período de de implantación leptina redujo las concentraciones de esters de cholesterol en controles y redujo los niveles de triglicéridos fosfolipidos y esteres de colesterol de embriones de ratas diabéticas. CONCLUSION: la leptina juega un rol en la regulacion de las concentraciones de y la homeostasis lipidica durante la organogénesis embrionaria y la ausencia de insulina en un ambiente diabético causa una reducción da las concentraciones de leptina en embriones de ratas.
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