Renal tubular apoptosis after release of ureteral obstruction in the rat kidney.
BACKGROUND
Information concerning the mechanisms underlying recovery from hydronephrosis is limited. The frequency of apoptosis during healing from hydronephrosis was studied using a rat kidney model.


METHODS
The presence of apoptosis was studied using an in situ DNA 3' end labeling method, electron microscopy, and agarose gel electrophoresis.


RESULTS
The degree of apoptosis in both the medulla and cortex gradually increased during ureteral obstruction as shown by in situ DNA 3' end labeling. Release of the ureteral obstruction resulted in a further increase in the degree of apoptosis in the medulla and cortex. The increase in apoptosis in the medulla was transient and lasted for only 4 days following release, while that in the cortex continued for at least 3 weeks. Apoptosis in the glomerulus was not observed. Electron microscopy revealed cells with aggregated chromatin in compact granular masses that abutted the nuclear membrane. Following release of ureteral obstruction, DNA fragmentation characteristic of apoptosis was visible on agarose gel electrophoresis.


CONCLUSIONS
These results suggest that apoptosis is involved in post-obstructive tubular damage in the rat kidney.
Tanji
N
N
Department of Urology, Ehime University Medical School, Japan.
Yokoyama
M
M
Terada
N
N
Shudo
M
M
Takeuchi
K
K
Takeuchi
M
M
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D053938:DNA Fragmentation / Q000502:physiology; D004587:Electrophoresis, Agar Gel; D005821:Genetic Techniques; D007684:Kidney Tubules / Q000473:pathology*; D008026:Ligation; D008297:Male; D008854:Microscopy, Electron; D051381:Rats; D017208:Rats, Wistar; D014517:Ureteral Obstruction / Q000235:genetics / Q000473:pathology*