CLAUDIA MARIA DE BARROS HELOU
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/12 - Laboratório de Pesquisa Básica em Doenças Renais, Hospital das Clínicas, Faculdade de Medicina
LIM/12 - Laboratório de Pesquisa Básica em Doenças Renais, Hospital das Clínicas, Faculdade de Medicina
4 resultados
Resultados de Busca
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- Maternal Hypercholesterolemia Associated with Nicotine Exposure in Adulthood May Induce Kidney Injury in Male Rats if Hypomagnesemia Occurs(2017) HELOU, Claudia M. B.; VOLPINI, Rildo A.; SANTINHO, Mirela A. R.; FONSECA, Fabricio L.; SIMIAO, Andre L.Background/Aims: Maternal hypercholesterolemia is a risk factor to renal injury in rat pups at adulthood, especially if they feed a cholesterol-enriched diet after weaning. However, the renal function of male pups of dams with hypercholesterolemia (PH) that were fed a regular chow from weaning to adulthood needs investigation, particularly those exposed to an adverse risk such as nicotine. Methods: We evaluated the renal function of PH animals and we compared the data with those found in male pups of control dams (PC) at 3- and 6-month-old by inulin clearance. Moreover, we investigated the effect of nicotine treatment for 8 days in both PH and PC animals at 6 months old via metabolic function studies and by renal histological analysis. Results: Inulin clearance and other renal function parameters were similar in PH and PC animals at 3 and 6 months old. Nevertheless, the PH group showed significant differences with regard to histological analysis despite a similar number of glomeruli. The glomerular area of PH animals was significantly smaller than that measured in PC animals, and the fractional interstitial area was significantly larger in PH animals than that measured in PC animals at 3 months old. With regard to nicotine treatment, we observed a trend for a reduction in creatinine clearance in both PC and PH groups, but only PH animals showed hypomagnesemia and the highest fractional interstitial area. Conclusions: The offspring exposed to a high cholesterol milieu during intrauterine and neonatal life may show a silent kidney injury at adulthood that may be aggravated by nicotine exposure if hypomagnesemia occurs. (c) 2017 The Author(s) Published by S. Karger AG, Basel
- High Cholesterol Feeding May Induce Tubular Dysfunction Resulting in Hypomagnesemia(2012) FAVARO, Vanessa F.; OSHIRO-MONREAL, Fabiola M.; BRAGANCA, Ana Carolina de; ANDRADE, Lucia; SEGURO, Antonio Carlos; HELOU, Claudia M. B.Background/Aims: Hypomagnesemia may induce hypercholesterolemia, but the contrary has not been described yet. Thus, magnesium homeostasis was evaluated in rats fed a cholesterol-enriched diet for 8 days. This study has a relevant clinical application if hypomagnesemia, due to hypercholesterolemia, is confirmed in patients with long-term hypercholesterolemia. Methods: Both hypercholesterolemic (HC) and normocholesterolemic rats (NC) were divided into sets of experiments to measure hemodynamic parameters, physiological data, maximum capacity to dilute urine (C-H2O), variations (Delta) in [Ca2+](i) and the expression of transporter proteins. Results: HC developed hypomagnesemia and showed high magnesuria in the absence of hemodynamic abnormalities. However, the urinary sodium excretion and C-H2O in HC was similar to NC. On the other hand, the responses to angiotensin II by measuring Delta [Ca2+](i) were higher in the thick ascending limb of Henle's loop (TAL) of HC than NC. Moreover, high expression of the cotransporter NKCC2 was found in renal outer medulla fractions of HC. Taken together, the hypothesis of impairment in TAL was excluded. Actually, the expression of the epithelial Mg2+ channel in renal cortical membrane fractions was reduced in HC. Conclusion: Impairment in distal convoluted tubule induced by hypercholesterolemia explains high magnesuria and hypomagnesemia observed in HC.
- Chronic nicotine exposure reduces klotho expression and triggers different renal and hemodynamic responses in klotho-haploinsufficient mice(2018) COELHO, Fernanda Oliveira; JORGE, Lecticia Barbosa; VICIANA, Ana Carolina de Braganca; SANCHES, Talita R.; SANTOS, Fernando dos; HELOU, Claudia M. B.; IRIGOYEN, Maria Claudia; KURO-O, Makoto; ANDRADE, LuciaThe klotho gene, which encodes a single-pass transmembrane protein and a secreted protein, is expressed predominantly by the distal renal tubules and is related to calcium phosphorus metabolism, ion channel regulation, intracellular signaling pathways, and longevity. Klotho deficiency aggravates acute kidney injury and renal fibrosis. Exposure to nicotine also worsens kidney injury. Here, we investigated renal Klotho protein expression in a mouse model of chronic (28-day) nicotine exposure, in which mice received nicotine or vehicle (saccharine) in chinking water, comparing wild-type (WT) mice, klotho-haploinsufficient (kl/+) mice, and their respective controls, in terms of the effects of that exposure. Nicotine exposure was associated with a significant decline in renal Klotho expression in WT and kl/+ mice as well as a reduction in the glomerular filtration rate in WT mice. Although plasma electrolytes were similar among the groups, fractional excretion of sodium was reduced in both nicotine-exposed groups. The nicotine-WT mice presented augmented baroreflex sensitivity to nitroprusside and augmented sympathetic cardiac modulation. However, nicotine-kl/+ mice presented higher plasma levels of urea and aldosterone together with a higher alpha-index (spontaneous baroreflex) and higher peripheral sympathetic modulation, as evaluated by spectral analysis. We can conclude that nicotine downregulates Klotho expression as well as that renal and autonomic responses to nicotine exposure are modified in kl/+ mice.
- Rosiglitazone Did Not Induce Acute Kidney Injury in Normocholesterolemic Rats Despite Reduction in Glomerular Filtration Rate(2013) DIAS, Cristiano; VOLPINI, Rildo A.; HELOU, Claudia M. B.Background/Aims: Rosiglitazone (RGL) has been used to ameliorate lipids homeostasis and also to treat inflammatory diseases. However, RGL may reduce renal blood flow and glomerular filtration rate (GFR) predisposing to acute kidney injury (AKI). We investigated whether the treatment with RGL induces AKI in normocholesterolemic (NC) and hypercholesterolemic (HC) rats. Methods: We measured GFR by inulin clearance technique and we quantified urinary neutrophil gelatinase-associated lipocalin (uNGAL) in all groups at baseline and during Ang II-stimulated vasoconstriction. Moreover, we evaluated the presence of renal damaged by histologic examination. Results: At baseline, NC and HC had normal and similar GFR. RGL treatment reduced GFR only in NC+RGL. Unexpectedly, HC+RGL showed high levels of uNGAL although GFR was at normal range. During Ang II-stimulated vasoconstriction, all groups showed reduction in GFR to the same range and we found high levels of uNGAL and high score of renal damage in HC and HC+RGL. Conclusion: RGL acts distinctly in normocholesterolemia and in hypercholesterolemia. Reduction in GFR provoked by RGL treatment did not allow the diagnosis of AKI in NC even in the presence of ANG II-stimulated vasoconstriction. However, AKI was diagnosed in HC+RGL at baseline although GFR was within normal range.