cytochrome-c-t and Kidney-Calculi

Reactive oxygen species play important roles in renal calcium crystallization. In this study, we examined the effects of catechin, which have been shown to have antioxidant properties on the renal calcium crystallization.. In the vitro experiment, the changes of the mitochondrial membrane potential, expression of superoxide dismutase (SOD), 4-hydroxynonenal (4-HNE), cytochrome c, and cleaved caspase 3 were measured to show the effects of catechin treatment on the NRK-52E cells induced by calcium oxalate monohydrate (COM). In the vivo study, Sprague-Dawley rats were administered 1% ethylene glycol (EG) to generate a rat kidney stone model and then treated with catechin (2.5 and 10 mg/kg/day) for 14 days. The urine and serum variables were dected on 7 and 14 days after EG administration. The expression of cytochrome c, cleaved caspase 3, SOD, osteopontin (OPN), malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG) in kidney were measured. Furthermore, the mitochondrial microstructure in the kidney was also examined by transmission electron microscopy.. Catechin treatment could prevent the changes in mitochondrial membrane potential and expression of SOD, 4-HNE, cytochrome c, and cleaved caspase 3 in NRK-52E cells induced by the COM. For the in vivo experiments, the EG administration induced renal calcium crystallization was also prevented by the catechin. The expression of SOD, OPN, MDA, OPN and 8-OHdG, were increased after EG administration and this increase was diminished by catechin. Moreover, catechin also prevented EG induced mitochondrial collapse in rat.. Catechin has preventive effects on renal calcium crystallization both in vivo and in vitro, and provide a potential therapeutic treatment for this disease.

Topics: Animals; Antioxidants; Calcium Oxalate; Caspase 3; Catechin; Cell Line; Crystallization; Cytochromes c; Ethylene Glycol; Immunohistochemistry; Kidney; Kidney Calculi; Male; Membrane Potential, Mitochondrial; Osteopontin; Protective Agents; Rats; Rats, Sprague-Dawley; Superoxide Dismutase

Calcium oxalate monohydrate (COM) crystals are the commonest component of kidney stones. Oxalate and COM crystals in renal cells are thought to contribute to pathology via prooxidant events. Using an in vivo rat model of crystalluria induced by hyperoxaluria plus hypercalciuria [ethylene glycol (EG) plus 1,25-dihydroxycholecalciferol (DHC)], we measured glutathione and energy homeostasis of kidney mitochondria. Hyperoxaluria or hypercalciuria without crystalluria was also investigated. After 1-3 wk of treatment, kidney cryosections were analyzed by light microscopy. In kidney subcellular fractions, glutathione and antioxidant enzymes were measured. In mitochondria, oxygen consumption and superoxide formation as well as cytochrome c content were measured. EG plus DHC treatment increased formation of renal birefringent crystal. Histology revealed increased renal tubular pathology characterized by obstruction, distension, and interstitial inflammation. Crystalluria at all time points led to oxidative stress manifest as decreased cytosolic and mitochondrial glutathione and increased activity of the antioxidant enzymes glutathione reductase and -peroxidase (mitochondria) and glucose-6-phosphate dehydrogenase (cytosol). These changes were followed by a significant decrease in mitochondrial cytochrome c content at 2-3 wk, suggesting the involvement of apoptosis in the renal pathology. Mitochondrial oxygen consumption was severely impaired in the crystalluria group without increased mitochondrial superoxide formation. Some of these changes were also evident in hyperoxaluria at week 1 but were absent at later times and in all calciuric groups. Our data indicate that impaired electron flow did not cause superoxide formation; however, mitochondrial dysfunction contributes to pathological events when tubular crystal-cell interactions are uncontrolled, as in kidney stones disease.

Topics: Animals; Calcium; Calcium Oxalate; Cytochromes c; Cytosol; Disease Models, Animal; Energy Metabolism; Glutathione; Kidney; Kidney Calculi; Male; Mitochondria; Oxalates; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reference Values