Reduced number of glomeruli in kidneys with neonatally induced partial ureteropelvic obstruction in pigs.
OBJECTIVE
We quantify the structural components of the nephron in adult pig kidneys with neonatally induced unilateral hydronephrosis in comparison with nonobstructed kidneys.


METHODS
The study included 11 pigs with unilateral partial ureteropelvic obstruction induced 2 days after birth and 8 sham operated control pigs. Obstructed kidney glomerular filtration rate was significantly reduced at age 4 weeks but did not differ from control kidneys after 24 weeks. At age 24 weeks the kidneys were perfusion fixed, and the number and volume of glomeruli and tubular lengths were measured using stereological methods.


RESULTS
Mean obstructed kidney volume did not differ from that of control kidneys. Mean number plus or minus standard deviation of glomeruli in the obstructed kidneys was reduced by 28% compared to that of control kidneys (502 +/- 163 x 103 versus 697 +/- 161 x 103, p = 0.02), whereas no difference in mean glomerular volume was observed. Mean length of the proximal or distal tubules did not differ between obstructed and control kidneys. Mean number or volume of glomeruli in nonobstructed kidneys contralateral to obstructed kidneys did not differ from that of control kidneys. The individual number of glomeruli in the obstructed kidneys was not associated with function of these kidneys.


CONCLUSIONS
Neonatally induced unilateral partial ureteropelvic obstruction causes impaired nephrogenesis with a significant reduction in the number of nephrons, which is not reflected in measurements of kidney function in this model. The reduction in the number of glomeruli suggests that congenital unilateral obstruction impairs nephrogenesis.
Eskild-Jensen
Anni
A
Institute of Experimental Clinical Research, Stereological Research Laboratory and Electron Microscopy Laboratory, University of Aarhus, Denmark.
Frøkiaer
Jørgen
J
Djurhuus
Jens Christian
JC
Jørgensen
Troels Munich
TM
Nyengaard
Jens Randel
JR
D000818:Animals; D000831:Animals, Newborn; D005260:Female; D005919:Glomerular Filtration Rate; D007678:Kidney Glomerulus / Q000473:pathology*; D007686:Kidney Tubules, Distal / Q000473:pathology; D007687:Kidney Tubules, Proximal / Q000473:pathology; D013552:Swine; D014517:Ureteral Obstruction / Q000473:pathology* / Q000503:physiopathology