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Vitamin E protects against the mitochondrial damage caused by cyclosporin A in LLC-PK1 cells.

Cyclosporin A (CsA) has nephrotoxic effects known to involve reactive oxygen species (ROS), since antioxidants prevent the kidney damage induced by this drug. Given that mitochondria are among the main sources of intracellular ROS, the aims of our study were to examine the mitochondrial effects of CsA in the porcine renal endothelial cell line LLC-PK1 and the influence of the antioxidant Vitamin E (Vit E). Following the treatment of LLC-PK1 cells with CsA, we assessed the mitochondrial synthesis of superoxide anion, permeability transition pore opening, mitochondrial membrane potential, cardiolipin peroxidation, cytochrome c release and cellular apoptosis, using flow cytometry and confocal microscopy procedures. Similar experiments were done after Vit E preincubation of cells. CsA treatment increased superoxide anion in a dose-dependent way. CsA opened the permeability transition pores, caused Bax migration to mitochondria, and decreased mitochondrial membrane potential and cardiolipin content. Also CsA released cytochrome c into cytosol and provoked cellular apoptosis. Vit E pretreatment inhibited the effects that CsA induced on mitochondrial structure and function in LLC-PK1 cells and avoided apoptosis. CsA modifies mitochondrial LLC-PK1 cell physiology with loss of negative electrochemical gradient across the inner mitochondrial membrane and increased lipid peroxidation. These features are related to apoptosis and can explain the cellular damage that CsA induces. As Vit E inhibited these effects, our results suggest that they were mediated by an increase in ROS production by mitochondria.

Papel del nefrólogo en la acidosis láctica grave por metformina

Metformin is an antihyperglycemic agent commonly used in diabetic patients. It is very effective and is able to reduce the plasma glucose and HbA1C. However, in some patients, specially those with comorbidities, metformin can provoke severe lactic acidosis with high morbimortality. Treatment of the lactic acidosis induced by metformin is based on the use of supportive general measures; in severe cases, procedures of extrarrenal purification like hemodialysis or continuous hemodiafiltration have been successfully used.

Glomerulopatía C3: una nueva entidad basada en el complemento

C3 glomerulopathy is a new, recently described entity that has changed the perspective, treatment and classification of a number of glomerular diseases. It encompasses 2 similar but clearly differentiated pathologies -the dense-deposit disease and C3 glomerulonephritis itself. The alternative complement pathway plays a fundamental role in its pathogenesis and, specifically, the mutations and defects in its regulatory factors (mainly factor H and factor I), as well as the presence of acquired autoantibodies (C3 nephritic factor), which generates an unbridled activation of the system, and ultimately, a deposit of its products at the glomerular level. Its poor prognosis and onset in young populations makes the detailed study of new therapeutic alternatives for this disease essential. Recently eculizumab, an anti-C5 antibody, has demonstrated effectiveness in the treatment of these patients.

Feocromocitoma con consecuencias fatales. ¿Qué podemos aprender de este caso?

Resumen Describimos el caso de un paciente de 42 anos que desarrollo shock cardiogenico con elevacion de enzimas cardiacas y coronariografia normal, cuyo diagnostico final fue feocromocitoma. El paciente tuvo una evolucion torpida con fracaso multiorganico y necesidad de intubacion orotraqueal, balon de contrapulsacion y hemodiafiltracion continua. Finalmente tuvo hematoma parenquimatoso cerebral con deterioro neurologico irreversible. Ademas destacamos el papel de la ecografia abdominal en el diagnostico de feocromocitoma en pacientes criticos.