Corticomedullary procollagen alpha1(IV) mRNA levels and localization after subtotal nephrectomy.
The relationships between tubular hypertrophy/hyperplasia, procollagen alpha1(IV) mRNA levels, and the development of tubular basement membrane thickening were studied in male Sprague-Dawley rats subjected to subtotal renal ablation and sacrificed 2 or 15 days later. Tubular hypertrophy and hyperplasia were demonstrable at 2 days, however no increment in procollagen alpha1 (IV) mRNA levels was discerned at that time, demonstrating a dissociation between mRNA levels for classical type IV collagen and tubular enlargement. At 15 days, tubular procollagen alpha1(IV) mRNA levels did increase approximately 2-fold (p < 0.002), localizing predominantly in proximal tubules in the deep cortex and outer medullary stripe. At this time point, there was still no significant correlation to tubular enlargement, but there was a significant correlation to tubular basement membrane thickening (r = 0.89, p < 0.01). These studies demonstrated that an increase in mRNA for classical type IV collagen is not required for the development of hypertrophy, and that the increment is a better marker for matrix expansion than it is for hypertrophy.
Adler
S G
SG
Department of Medicine, Harbor-UCLA Medical Center/Cedars-Sinai Medical Center, Torrance/Los Angeles, Calif 90509, USA. adler@harbor2.humc.edu
Lee
G S
GS
Cohen
A H
AH
Nast
C C
CC
D000199:Actins / Q000235:genetics; D000818:Animals; D001345:Autoradiography; D001485:Basement Membrane / Q000473:pathology; D015342:DNA Probes; D006965:Hyperplasia; D006984:Hypertrophy; D017403:In Situ Hybridization; D007672:Kidney Cortex / Q000737:chemistry* / Q000473:pathology; D007679:Kidney Medulla / Q000737:chemistry* / Q000473:pathology; D007687:Kidney Tubules, Proximal / Q000737:chemistry / Q000473:pathology; D008297:Male; D009392:Nephrectomy; D011347:Procollagen / Q000235:genetics*; D015347:RNA Probes; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000199:Actins; D015342:DNA Probes; D011347:Procollagen; D015347:RNA Probes; D012333:RNA, Messenger