Dietary polyunsaturated fatty acids slow the progression of diabetic nephropathy in streptozotocin-induced diabetic rats.
Diabetic nephropathy is associated with lipid deposits in the kidney. We hypothesized that a diet containing polyunsaturated fatty acids (PUFAs) could ameliorate pathogenesis of diabetic kidney diseases associated with lipid depositions in the kidneys. We examined if the pathogenesis and progression of diabetic nephropathy are affected by the type of dietary fat using streptozotocin (45 mg/kg body weight, intravenous)-induced diabetic rats (5-week-old male Sprague-Dawley rats). Streptozotocin-induced diabetic rats were fed a lard diet containing saturated fatty acids or a rapeseed oil diet containing PUFAs (DML and DMR, respectively) for 11 days. Similarly, streptozotocin-nontreated rats were fed a lard diet or a rapeseed oil diet (NL and NR, respectively) for 11 days. Hyperglycemia was induced in DML and DMR, compared with NL and NR groups. The levels of plasma ketone, total cholesterol, and triglyceride (TG) were significantly increased in the DML group. Moreover, albuminuria and renal TG content were enhanced in the DML group. The renal TG content correlated positively with urinary albumin excretion (P < .001). Oil-Red O staining of kidney sections indicated a marked accumulation of neutral lipids in both glomerular and tubular cells in the DML group. In addition, a renal sterol regulatory element-binding protein-1 mature protein increment was induced in the DML group. Conversely, sterol regulatory element-binding protein-1 expression in the kidney was maintained at normal levels in the DMR group. These results suggest that dietary PUFAs may slow the progression of diabetic nephropathy associated with lipid depositions in the kidney.
Yokoyama
Meiko
M
Graduate School of Human Environment Science, Kyoto Prefectural University, Kyoto 606-8522, Japan.
Tanigawa
Kanae
K
Murata
Tomoko
T
Kobayashi
Yukiko
Y
Tada
Eriko
E
Suzuki
Isao
I
Nakabou
Yukihiro
Y
Kuwahata
Masashi
M
Kido
Yasuhiro
Y
D000419:Albuminuria; D000818:Animals; D001391:Azo Compounds; D002467:Cell Nucleus / Q000737:chemistry; D002784:Cholesterol / Q000097:blood; D004396:Coloring Agents; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000150:complications*; D003928:Diabetic Nephropathies / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D004041:Dietary Fats / Q000008:administration & dosage; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage*; D007659:Ketones / Q000097:blood; D007668:Kidney / Q000737:chemistry / Q000648:ultrastructure; D008055:Lipids / Q000032:analysis; D008099:Liver / Q000737:chemistry; D008297:Male; D010938:Plant Oils / Q000008:administration & dosage; D012333:RNA, Messenger / Q000032:analysis; D011897:Random Allocation; D000074262:Rapeseed Oil; D051381:Rats; D017207:Rats, Sprague-Dawley; D051780:Sterol Regulatory Element Binding Protein 1 / Q000032:analysis / Q000235:genetics; D014280:Triglycerides / Q000032:analysis / Q000097:blood
D001391:Azo Compounds; D004396:Coloring Agents; D004041:Dietary Fats; D004042:Dietary Fats, Unsaturated; D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated; D007659:Ketones; D008055:Lipids; D010938:Plant Oils; D012333:RNA, Messenger; D000074262:Rapeseed Oil; C497389:Srebf1 protein, rat; D051780:Sterol Regulatory Element Binding Protein 1; D014280:Triglycerides; D002784:Cholesterol; C011049:oil red O; C029310:lard