In a counterintuitive result, researchers found that giving male rats a low dose of the endotoxin lipopolysaccharide (LPS) prior to inducing a model of acute kidney injury (AKI) improved outcomes. Their study will be presented at the 2019 American Physiological Society (APS)/American Society of Nephrology (ASN) Conference, Control of Renal Function in Health and Disease in Charlottesville, VA.
AKI is a loss of kidney function that occurs within a few hours or days. It is a common and growing in-hospital complication, occurring in one in 5 patients. According to the U.S. CDC, it is associated with high hospital mortality, increased healthcare costs, need for long-term care, and risk of chronic kidney disease. Diabetes is a risk factor for AKI. As the number of people diabetes with continues to increase, rates of AKI are expected to grow as well.
LPS is a toxic compound found in the cell membrane of some types of bacteria, including Escherichia coli (E. coli) and salmonella. It can be a factor in the development of septic shock. In a research setting, LPS is used to trigger and then study innate immune responses and inflammation.
In this study, researchers administered either saline or low-dose LPS to cohorts of male and female rats daily for seven days. After seven days, they induced a model of restricted blood supply-induced AKI. They then examined the blood and tissue for markers related to inflammation, kidney injury and red blood cell congestion in the innermost part of the kidney, a hallmark of this type of AKI.
Males showed a dose-dependent increase in a measure of inflammation called the erythrocyte sedimentation rate. Females, however, showed no difference from the saline control group. Males that received the low-dose LPS showed less red blood cell congestion than other groups despite increased inflammation. All female groups resembled their control.
