Methods for Assessment of the Glomerular Filtration Rate in Laboratory Animals

Background: The glomerular filtration rate (GFR), as the benchmark of renal function, has been widely used in clinical practice and basic medical research. Currently, most researchers still rely on endogenous markers, such as plasma creatinine, blood urea nitrogen, and cystatin C, to evaluate renal function in laboratory animals. While inexpensive and simple to use, methods based on endogenous markers are often inaccurate and susceptible to several internal physiological factors. Thus, it is necessary to establish a method to precisely assess the GFR, especially when detecting early changes in GFR during acute kidney injury, and hyperfiltration usually caused by pregnancy or diabetic nephropathy. In addition, laboratory animals have higher tolerance for invasive procedures than humans, allowing novel technologies to be applied on them for GFR monitoring. In recent years, significant progress has been made in developing new methods to assess GFR in animals. However, no publication has reviewed these techniques. Summary: This article summarized the majority of methods used to assess the GFR in animals in recent decades and discussed their working principles, workflows, advantages, and limitations, providing a wealth of reference and information for researchers interested in studying the kidney function in animals and developing techniques to monitor the GFR.