Transforming growth factor-beta in the development of rat diabetic nephropathy. A 10-month study with insulin-treated rats.
We investigated the intrarenal distribution of transforming growth factor-beta 1 (TGF-beta 1) protein and the TGF-beta 1 mRNA levels in the glomeruli and renal cortex of Wistar rats with streptozotocin-induced diabetes before and after the onset of diabetic nephropathy. Monthly urinary albumin excretion, glomerular filtration rate, glomerular volume, renal histology and immunohistochemical reaction for type-I collagen were also studied. The results showed progressively higher glomerular immunohistochemical TGF-beta 1 staining in rats with a diabetes duration of 24 and 40 weeks which was correlated with albuminuria (r = 0.905, p < 0.01) and was temporally associated with the appearance of glomerular deposition of total and type-I collagen. The glomerular content of TGF-beta 1 mRNA was higher in rats diabetic for 20 weeks while lower cortical RNA-TGF-beta 1 levels were found in rats with a diabetes duration of 1-40 weeks. These data suggest that this polypeptide may be an important mediator of diabetic glomerulosclerosis.
Bertoluci
M C
MC
Curso de Pós-Graduacão, Clinica Médica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Schmid
H
H
Lachat
J J
JJ
Coimbra
T M
TM
D000818:Animals; D015152:Blotting, Northern; D003928:Diabetic Nephropathies / Q000139:chemically induced / Q000188:drug therapy / Q000378:metabolism*; D005260:Female; D006943:Hyperglycemia / Q000378:metabolism; D007150:Immunohistochemistry; D007328:Insulin / Q000494:pharmacology*; D007672:Kidney Cortex / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D007677:Kidney Function Tests; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D012598:Sclerosis; D016212:Transforming Growth Factor beta / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*
D007328:Insulin; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta