• Journal of Nutrition and Health
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• v.29 no.10
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• pp.1059-1071
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• 1996

This study was performed to investigate the effect of dietary protein level on renal senescence. Male rats of 337.8$\pm$5.7g body weight were underlateral nephrectomy or shamoperation. The rats were divided into high protein(40% casein), normal protein(15% casein) and low protein(8% casein)diets and fed experimental diets ad libitum for 24 weeks. The results are summarized as follows. There was a hypertophy of the remnant kidney of uninephrectomized rats of 40% or 15% protein group, coming up to the comparable weights of both kidneys of sham-operated rats. However, the hypertrophic effect was not seen in uninephrectomized rats of 8% protein group. Serum albumin was lower in uninephrectomized rats. With increasing dietary protein level blood urea nitrogen was increased, whereas, urinary urea nitrogen excretion was decreased. Urinary solute excretion was higher in uninephrectomized group than in sham-operated group. However, effect of dietary protein level on urinary solute excretion varied dpending on th solutes tested. GFR and urinary protein excretion, throughout experiment, increased with feeding period and with dietary protein level. Proteinuria was most severe in uninephrectomized rats fed 40% casein diet. Maximum urine concentration ability measured after dehydration was not different among the experimental groups. Light microscopic examination showed focal segmental glomerulosclerosis and mild increas of glomerular mesangial matrix in uninephrectomized rats fed 40% and 15% protein diet, however, which was not observed in uninephrectomized rats fed 8% protein diet and in sham-operated rats fed 40% diet. Immunofluorescence studies revealed segmental deposits of albumin in the mesangium and capillary loops in high protein and uninephrectomized groups. Minimal granular deposition of IgG was noted in the mesangium of all experimental groups. In conclusion, high protein intake accelerated deterioration of renal function and it was correlated with morphological change. Low protein intake was effective in preventing these changes.

• Biomolecules & Therapeutics
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• v.6 no.2
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• pp.130-138
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• 1998

In this study, the effect of verapamil (VER) on cyclosporin A (CsA)-induced nephrotoxicity was investigated in uninephrectomized rats. Male Wistar rats were administered CsA (50 mg/kg/day, p.o.) or VER (0.5 mg/kg/day, i.p.) with CsA (50 mg/kg/day, p.o.) for 20 days. The urinary N-acetyl-$\beta$-D-glucosaminidase (NAG) activity along with BUN, serum creatinine, creatinine clearance (CLcr), body weight, and 24 hr-urine output were measured and histopathologic changes of kidney were evaluated by light and electron microscopy. The results obtained from this study can be summarized as follows: While NAG activity, BUN and serum creatinine was progressively increased and CLcr significantly decreased in CsA group, VER almost signifi-cantly (p<0.05) suppressed and normalized CsA-induced changes in VER+CSA group. While urine output increased until 12th days and thereafter progressively decreased in CsA group, it gradually increased in control and VER+CSA group. While body weight progressively made a gain in control and VER+CSA groups, it significantly (p<0.05) lost in CsA group. On light microscopy, the glomerular hyperemia and proximal convoluted tubular (PCT) dilatation, focal tubular cell vacuolation and necrosis were clearly evident in CsA group, but, were not seen in other groups. Ultrastructural studies revealed thickened glomerular endothelium and basal lamina of capillary, irregular shaped pedicels of podocytes, indistinct slit pores and narrowed bowman's space. The large oval vacuoles with dense debris and phagosome were distributed in apical zone and deformed microvilli and mitochondria were seen in the PCT cell of CsA group. But, glomeruli and PCT cell were relatively preserved in normal apperance in other groups. In conclusion, it is suggested that verapamil has a protective effect on cyclosporine-induced nephrotoxicity in uninephrectomized rats.

• Journal of Nutrition and Health
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• v.34 no.4
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• pp.359-366
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• 2001

Studies were carried out to explore the influence of dietary protein level on bone metabolism in uninephrectomized rat (experimental renal failure model) when dietary Ca and P contents were equal. Male rats were uninephrectomized or sham operated and fed 8%, 15% and 40% casein diets for 24 weeks. Ca and P contents of the all diet were 0.4% and 0.6% respectively. The results are summarized as follows. We did not found any significant difference in PTH and Ca level of the serum, Ca intake and Ca excretion among the experimental groups. There was significant positive correlation between the PTH and phosphate level. There was significant inverse correlation between serum Ca and creatinine level. The effect of the dietary protein level and renal mass loss on density and Ca contents of the bone were small and different according to the kinds of the bone. Low protein diet was associated with a significant enhancement of scapular density. Femur and vertebra density, however, were not influenced by dietary protein level and uninephrectomy. Light microscopic examination showed several calcified foci in the kidney in all experimental groups. Low protein diets have been used for a long time in the conservative management of chronic renal failure as they have a beneficial effect in preventing the appearance of symptoms. This study elucidated that part of beneficial effects of the low protein diet related to the suppression of the hyperphosphatemia. And these results, even though uninephrectomized rats fed high protein diet, the secondary hyperparathyroidism is supressed by the regulation of the P level. Therefore this study emphasized the need to pay more attention to the regulation of dietary P level as well as dietary protein content in chronic renal failure. (Korean J Nutrition 34(4): 359∼366, 2001)

• Journal of Acupuncture Research
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• v.15 no.2
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• pp.43-60
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• 1998

This study examined the histomorphomeric and histological changes of the left and right kidney in uninephrectomized rat. The results were as follows: 1. In the control, the right kidney was more prominent than the left in the basement membrane of glomerular capillaries. The podocyte had well developed Golgi apparatus in the left kidney and rough endoplasmic reticulum in the right kidney. 2. At the 30 days after unilateral nephrectomy, the basal lamina of glomerular capillaries was prominently thickened in the right kidney. The cytoplasm of the podocyte of the left kidney was markedly increased and had free ribosomes, developed Golgi apparatus and rough endoplasmic reticulum. 3. At the 30 days, the section of the glomeruli were more enlarged in the left kidney than in the right. 4. At the 20 day, the nuclear section of the podocytes were markedly enlarged in the right kidney, but those of the left kidney were diminished. The mitochondrial section of the podocytes were prominently increased in the right kidney. 5. The nuclear section of the parietal layer lining cells was no significant change in the right kidney. That of the left kidney was increased at the 20 days and decreased at the 40 days. The nuclear section of glomerular endothelium of the left kidney increased earlier than the right. 6. In the morphometry of the control kidney, the section areas, long and short diameters, the nuclear section, the mitochondrial section of the proximal tubule cells, and the changes of those were more large in the right kidney than in the left. 7. The luminal secretory vesicles and peroxisomes of the left kidney were more than the right at the 20 days. The increase of mitochodrial section in the proximal tubule cells of the left kidney was more prominent than the right. The large cytoplasmic vacuoles were more prominent in the left kidney than in the right. 8. The thickness of cytoplasm and brush border was more thick in the control left kidney than in the control right. The change of cytoplasmic thickness of the left kidney was increased earlier than in the right and both kineys were increased in the thickness of brush border at the 30 days.