Effect of D-alpha-tocopherol on tubular nephron acidification by rats with induced diabetes mellitus.
The objective of the present study was to determine if treatment of diabetic rats with D-alpha-tocopherol could prevent the changes in glomerular and tubular function commonly observed in this disease. Sixty male Wistar rats divided into four groups were studied: control (C), control treated with D-alpha-tocopherol (C + T), diabetic (D), and diabetic treated with D-alpha-tocopherol (D + T). Treatment with D-alpha-tocopherol (40 mg/kg every other day, ip) was started three days after diabetes induction with streptozotocin (60 mg/kg, ip). Renal function studies and microperfusion measurements were performed 30 days after diabetes induction and the kidneys were removed for morphometric analyses. Data are reported as means +/- SEM. Glomerular filtration rate increased in D rats but decreased in D + T rats (C: 6.43 +/- 0.21; D: 7.74 +/- 0.45; D + T: 3.86 +/- 0.18 ml min-1 kg-1). Alterations of tubular acidification observed in bicarbonate absorption flux (JHCO3) and in acidification half-time (t/2) in group D were reversed in group D + T (JHCO3, C: 2.30 +/- 0.10; D: 3.28 +/- 0.22; D + T: 1.87 +/- 0.08 nmol cm-2 s-1; t/2, C: 4.75 +/- 0.20; D: 3.52 +/- 0.15; D + T: 5.92 +/- 0.19 s). Glomerular area was significantly increased in D, while D + T rats exhibited values similar to C, suggesting that the vitamin prevented the hypertrophic effect of hyperglycemia (C: 8334.21 +/- 112.05; D: 10,217.55 +/- 100.66; D + T: 8478.21 +/- 119.81 microm(2)). These results suggest that D-alpha-tocopherol is able to protect rats, at least in part, from the harmful effects of diabetes on renal function.
Nascimento Gomes
G
G
Departamento de Fisiologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brasil. guiomar@ecb.epm.br
Barbosa
F T
FT
Radaeli
R F
RF
Cavanal
M F
MF
Mello Aires
M
M
Zaladek Gil
F
F
D000141:Acidosis, Renal Tubular / Q000517:prevention & control*; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000652:urine*; D003928:Diabetic Nephropathies / Q000517:prevention & control*; D005919:Glomerular Filtration Rate; D007678:Kidney Glomerulus / Q000187:drug effects / Q000378:metabolism; D007684:Kidney Tubules / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009399:Nephrons / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D024502:alpha-Tocopherol / Q000494:pharmacology*
D000975:Antioxidants; D024502:alpha-Tocopherol