Different phenotypes of dysplastic kidney in obstructive uropathy in fetal lambs.
OBJECTIVE
The cause of cyst production in renal dysplasia is uncertain. The authors hypothesized that different patterns of renal dysplasia result from variations in the timing and site of the urinary tract obstruction.


METHODS
The authors operated on fetal lambs at 50 and 60 days' gestation. Male lambs underwent urethral and urachal ligation and female lambs unilateral ureteric ligation. They were delivered by cesarean section at 145 days' gestation and killed.


RESULTS
Of 12 lambs operated on at 50 days' gestation, 4 survived. Of 26 lambs operated on at 60 days, 21 survived. The authors identified 3 types of dysplastic kidneys. Type A, fibrotic kidneys (2.2 g) with no cysts and interstitial fibrosis. There were reduced numbers of proximal tubules, but distal tubules and collecting ducts persisted. (50-day obstruction, n = 5 kidneys); type B, Sponge-like kidneys (37g): these had large cysts with minimal interstitial fibrosis. (87% of 60-day uretheral and urachal ligation model n = 12 kidneys); Type C, Small kidneys (4.8 g) with no large cysts (60-day Ureteric ligation model n = 7 kidneys).


CONCLUSIONS
The authors produced 3 different types of renal dysplasia by creating urinary tract obstruction at different sites and gestational ages.
Kitagawa
H
H
St Marianna University School of Medicine, Division of Pediatric Surgery, 2-16-1, Sugao, Miyamae-ku, Kawasaki-shi, 216-8511, Japan.
Pringle
K C
KC
Koike
J
J
Zuccollo
J
J
Nakada
K
K
D000818:Animals; D005260:Female; D005865:Gestational Age; D007668:Kidney / Q000002:abnormalities*; D052177:Kidney Diseases, Cystic / Q000151:congenital*; D007686:Kidney Tubules, Distal / Q000002:abnormalities; D007687:Kidney Tubules, Proximal / Q000002:abnormalities; D008297:Male; D010641:Phenotype; D012737:Sex Factors; D014517:Ureteral Obstruction / Q000150:complications*; D014524:Urethral Obstruction / Q000150:complications*