The mechanism of myocardium and pancreas injury in rabbits with acute renal failure might be related to myeloperoxidase and membrane pump activities

Mesenteric lymph duct ligation after hemorrhagic shock enhances the ATP level and ATPase activity in rat kidneys

BACKGROUND

Kidney injury commonly occurs following hemorrhagic shock. This study aims to observe the effects of mesenteric lymph duct ligation (MLDL) on the adenosine triphosphate (ATP) levels and the cell membrane adenosine triphosphatase (ATPase) activity in the kidneys of rats subjected to hemorrhagic shock.

METHODS

Wistar rats were assigned into sham, shock, and ligation groups. The hemorrhagic shock model was established in the shock and ligation groups, and MLDL was performed in the ligation group after resuscitation. Renal homogenates were prepared to determine the ATP and ATPase levels at 90 min after hemorrhage and at 0, 1, 3, 6, 12, and 24 h after resuscitation.

RESULTS

The ATP levels, and the Na(+)-K(+)-ATPase, Mg(2+)-ATPase, Ca(2+)-ATPase, and Ca(2+)-Mg(2+)-ATPase activities in the renal tissue of the shock group were lower than those in the sham group at the multiple time points. Furthermore, the corresponding values in the ligation group were significantly higher than those in the shock group at multiple time points.

CONCLUSION

MLDL improves energy metabolism and enhances the ATPase activity in the kidneys of hemorrhagic shock rats, along with other mechanisms that alleviate renal injury after hemorrhagic shock.

Polymorphisms in the myeloperoxidase gene locus are associated with acute kidney injury-related outcomes

Myeloperoxidase (MPO) is a lysosomal enzyme that may be involved in oxidative stress-mediated kidney injury. Using a 2-step approach, we measured the association of 4 polymorphisms across the length of the MPO gene with systemic markers of oxidative stress; plasma MPO and urinary 15-F_2t-isoprostane levels. Adverse outcomes were measured in a primary cohort of 262 adults hospitalized with acute kidney injury, and a secondary cohort of 277 adults undergoing cardiac surgery with cardiopulmonary bypass and at-risk for postoperative acute kidney injury. Dominant and haplotype multivariable logistic regression analyses found a genotype-phenotype association in the primary cohort between rs2243828, rs7208693, rs2071409, and rs2759 MPO polymorphisms and both markers of oxidative stress. In adjusted analyses, all 4 polymorphic allele groups had 2-3-fold higher odds for composite outcomes of dialysis or in-hospital death or a composite of dialysis, assisted mechanical ventilation or inhospital death. The MPO T-G-A-T haplotype copy-number was associated with lower plasma MPO levels and lower adjusted odds for the composite outcomes. Significant but less consistent associations were found in the secondary cohort. In summary, our 2-step genetic association study identified several polymorphisms spanning the entire MPO gene locus and a common haplotype marker for patients at-risk for acute kidney injury.