Effects of Schizolobium parahyba extract on experimental Bothrops venom-induced acute kidney injury.

BACKGROUND: Venom-induced acute kidney injury (AKI) is a frequent complication of Bothrops snakebite with relevant morbidity and mortality. The aim of this study was to assess the effects of Schizolobium parahyba (SP) extract, a natural medicine with presumed anti-Bothrops venom effects, in an experimental model of Bothrops jararaca venom (BV)-induced AKI. METHODOLOGY: Groups of 8 to 10 rats received infusions of 0.9% saline (control, C), SP 2 mg/kg, BV 0.25 mg/kg and BV immediately followed by SP (treatment, T) in the doses already described. After the respective infusions, animals were assessed for their glomerular filtration rate (GFR, inulin clearance), renal blood flow (RBF, Doppler), blood pressure (BP, intra-arterial transducer), renal vascular resistance (RVR), urinary osmolality (UO, freezing point), urinary neutrophil gelatinase-associated lipocalin (NGAL, enzyme-linked immunosorbent assay [ELISA]), lactate dehydrogenase (LDH, kinetic method), hematocrit (Hct, microhematocrit), fibrinogen (Fi, Klauss modified) and blinded renal histology (acute tubular necrosis score). PRINCIPAL FINDINGS: BV caused significant decreases in GFR, RBF, UO, HcT and Fi; significant increases in RVR, NGAL and LDH; and acute tubular necrosis. SP did not prevent these changes; instead, it caused a significant decrease in GFR when used alone. CONCLUSION: SP administered simultaneously with BV, in an approximate 10∶1 concentration, did not prevent BV-induced AKI, hemolysis and fibrinogen consumption. SP used alone caused a decrease in GFR.

Cisplatin and hypomagnesemia.

Hypomagnesemia is a well known side-effect in patients receiving cisplatin-containing chemotherapy. Cisplatin induces hypomagnesemia through its renal toxicity possibly by a direct injury to mechanisms of magnesium reabsorption in the ascending limb of the loop of Henle as well as the distal tubule. Since the magnesium reabsorption process still remains to be fully characterized, the effect by cisplatin on this process remains uncertain. Hypomagnesemia is a frequent complication to chemotherapy with cisplatin affecting up to 90% of patients if no corrective measures are initiated. The clinical importance of this hypomagnesemia remains uncertain. Possible symptoms of hypomagnesemia can be impossible to distinguish from symptoms related to the underlying disease or the treatment with chemotherapy. Existing studies on how to supplement magnesium during treatment with cisplatin have focused mainly on the effect on serum magnesium values and erythrocyte magnesium concentrations but both parameters are poor indicators of body magnesium stores. As long as the relationship between hypomagnesemia and possible complications thereof remains poorly elucidated, it seems reasonable to try to avoid hypomagnesemia. The best results seem to be provided by adding magnesium to the pre- and posthydration fluids.

Secondary oxalosis: a cause of delayed recovery of renal function in the setting of acute renal failure.

Oxalosis, or calcium oxalate deposition in the tissues, may develop in patients with inherited disorders of oxalate metabolism or can occur secondary to other diseases. In this study, a case of renal oxalosis probably secondary to excessive parenteral vitamin C administration in a patient with acute post-traumatic oliguric renal failure is reported. Oxalate deposits may have contributed to further worsening and delayed recovery of renal function. The elimination of the source of excess vitamin C and its presumed effect on oxalate production, together with enhanced removal of oxalate during aggressive dialysis, resulted in prompt recovery of renal function. Secondary oxalosis represents a possible cause of delayed recovery of renal function in patients with acute renal failure who are receiving vitamin C supplementation if excess dosage of that supplementation is given. Vitamin C supplementation, if utilized, should be carefully monitored in patients receiving artificial renal replacement therapy.