Considerations for the evaluation of renal function in genetically engineered mice.

Transgenic and gene-targeting techniques have opened a new era of physiologic investigation: the field of functional genomics. The nearly exclusive use of the mouse in this discipline has necessitated the development and adaptation of sophisticated techniques for evaluating murine physiology at the cellular, tissue, organ and whole animal levels. Although many of the methodologies for exploring cardiorenal function have been successfully adapted from their use in the rat, there are important limitations and considerations that must be recognized when applying them in the mouse. Investigators have been successful in measuring a wide variety of functional variables at the whole kidney and even single nephron levels. Reviewed here are recent advances in the measurement of blood pressure, renal blood flow, whole kidney electrolyte excretion and clearance rates, single-nephron glomerular filtration rate and transport, and tubuloglomerular feedback.