Obstructive nephropathy in the pig. Possible roles for insulin-like growth factor I.
Kidney growth was investigated in 30-kg pigs after 72 h of unilateral ureteral obstruction. The data were compared to control kidneys from normal non-operated pigs at same weight. Kidney wet weight was determined. Cortex and medulla were separated, and from both regions RNA, DNA, protein and kidney tissue insulin-like growth factor I was determined. Unilateral obstruction caused a doubling of the wet hydronephrotic kidney weight and an ipsilateral 76% increase in total kidney protein content. RNA increased by 45% in the cortex and 76% in the medulla. Kidney protein in the contralateral cortex increased by 23% and RNA by 42%. In the hydronephrotic kidney DNA was reduced by 13% in the cortex and by 21% in the medulla. Contralaterally, DNA was the same as in the controls. Mean kidney insulin-like growth factor I increased sevenfold in the ipsilateral medulla but in the cortex it was the same as in the controls. Serum insulin-like growth factor I concentration was 1.7 +/- 1.1 micrograms/l in the hydronephrotic animals and 1.2 +/- 0.8 micrograms/l in controls. At this stage of obstruction, our data demonstrate (1) hydronephrotic growth that is most probably hyperplastic in the medulla, associated with an increase in medullary insulin-like growth factor I, (2) hyperplastic growth in the cortex, and (3) contralateral kidney growth that is mainly hypertrophic after 72 h of contralateral ureteral obstruction.
D000818:Animals; D004247:DNA / Q000032:analysis; D005260:Female; D006869:Hydronephrosis / Q000503:physiopathology; D006984:Hypertrophy; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000502:physiology*; D007668:Kidney / Q000737:chemistry / Q000473:pathology / Q000503:physiopathology*; D009929:Organ Size; D012313:RNA / Q000032:analysis; D011863:Radioimmunoassay; D013552:Swine; D014517:Ureteral Obstruction / Q000503:physiopathology*
D012313:RNA; D007334:Insulin-Like Growth Factor I; D004247:DNA