Magnetic resonance imaging of urea transporter knockout mice shows renal pelvic abnormalities.
Many transgenic and knockout mice with increased urine flow have structural abnormalities of the renal pelvis and inner medulla. Here, we used high resolution contrast enhanced T1-weighted magnetic resonance imaging of mice whose urea transporters UT-A1 and UT-A3 were deleted (UT-A1/3(-/-) mice) as a model for the in vivo study of such abnormalities. Three distinct variations in the appearance of the renal pelvis were found. These included normal kidneys with no accumulation of contrast agent in the renal pelvis; infrequent frank right-sided unilateral hydronephrosis with marked atrophy of the renal medulla; and a renal pelvic reflux pattern characterized by the presence of contrast agent in the renal pelvis surrounding the renal inner medulla but no substantial atrophy of the medulla. This last pattern was found in most of the advanced age UT-A1/3(-/-) mice and in aquaporin-1 knockout mice. The UT-A1/3(-/-) mice also had increased mean arterial blood pressures. Feeding the mice a low protein diet did not prevent development of their renal pelvic abnormalities. Our studies show that real time imaging of renal pelvic structure in genetically manipulated mice provides a tool for the non-destructive, temporal evaluation of kidney structure.
Jacob
Vinitha A
VA
Laboratory of Kidney and Electrolyte Metabolism, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892-1603, USA.
Harbaugh
Calista M
CM
Dietz
John R
JR
Fenton
Robert A
RA
Kim
Soo M
SM
Castrop
Hayo
H
Schnermann
Jurgen
J
Knepper
Mark A
MA
Chou
Chung-Lin
CL
Anderson
Stasia A
SA
D000818:Animals; D001284:Atrophy; D001794:Blood Pressure; D003952:Diagnostic Imaging; D007679:Kidney Medulla / Q000473:pathology; D007682:Kidney Pelvis / Q000002:abnormalities*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D026901:Membrane Transport Proteins / Q000235:genetics*; D051379:Mice; D018345:Mice, Knockout; D000096982:Urea Transporters
D026901:Membrane Transport Proteins; D000096982:Urea Transporters