Effect of Dietary Protein Restriction on the Development of Renal Failure after Subtotal Nephrectomy in Rats

1983 ◽  
Vol 65 (4) ◽  
pp. 399-406 ◽  
Author(s):  
A. M. El-Nahas ◽  
H. Paraskevakou ◽  
S. Zoob ◽  
A. J. Rees ◽  
D. J. Evans

1. We have examined the effect of a low protein diet on the development of glomerular sclerosis and progressive renal failure after subtotal nephrectomies in rats. 2. Two groups of male Sprague-Dawley rats were studied after five-sixths nephrectomy; group 1 were maintained on a normal diet (13.5 g day−1 kg−1 body weight) and group 2 were fed with a low protein diet (6 g day−1 kg−1 body weight). 3. Rats maintained on a low protein diet survived for longer, and had significantly less glomerular sclerosis and significantly greater glomerular filtration rates when the experiment ended after 7 months. 4. We conclude that dietary protein influences favourably the development of glomerular scarring and renal failure after subtotal nephrectomy in rats.

1995 ◽  
Vol 268 (2) ◽  
pp. F302-F308 ◽  
Author(s):  
S. R. Inman ◽  
N. T. Stowe ◽  
J. V. Nally ◽  
B. H. Brouhard ◽  
D. G. Vidt

The effect of dietary protein on renal function and on renal microvascular reactivity to angiotensin II was determined in rats fed a high-protein diet (40% protein), a low-protein diet (6% protein), or a normal diet (23% protein). Inulin clearance was higher in high-protein-fed rats (n = 7) than in rats fed a low-protein diet (n = 7), 0.88 +/- 0.14 (means +/- SE) vs. 0.54 +/- 0.07 ml.min-1.g kidney wt-1 (P < 0.05). We also used videomicroscopy to assess the effect of angiotensin II on the renal microcirculation in a hydronephrotic kidney preparation. The afferent and efferent arterioles constricted to angiotensin II and norepinephrine in both high- and low-protein-fed rats; this constriction was diminished to angiotensin II but not to norepinephrine, in rats fed a high-protein diet (-24.3 +/- 4.5, -20.2 +/- 4.2%) compared with rats fed a low-protein diet (-39 +/- 5.1, -39.1 +/- 5.7%). The vasoconstrictor responses to angiotensin II in rats fed a high-protein diet and a normal diet were significantly greater following inhibition of angiotensin II formation with captopril but not in low-protein-fed rats. The apparent high-endogenous level of angiotensin II among rats fed a high-protein diet may account for the diminished reactivity to exogenous angiotensin II. Thus alterations in intrinsic vascular reactivity to angiotensin II are not responsible for the altered hemodynamics associated with dietary protein.


2015 ◽  
Vol 26 (7) ◽  
pp. 729-735 ◽  
Author(s):  
Kate J. Claycombe ◽  
Emilie E. Vomhof-DeKrey ◽  
James N. Roemmich ◽  
Turk Rhen ◽  
Othman Ghribi

Endocrinology ◽  
2011 ◽  
Vol 152 (5) ◽  
pp. 1839-1847 ◽  
Author(s):  
Victor Dubois-Ferrière ◽  
Tara C. Brennan ◽  
Romain Dayer ◽  
René Rizzoli ◽  
Patrick Ammann

Elderly men and women with protein deficiencies have low levels of circulating IGF-I, and it is likely this contributes to reduced bone formation and increased bone resorption. We hypothesized that calcitropic hormones are involved in this effect and are affected by dietary protein. We therefore investigated the influence of a low-protein diet on the PTH-1,25-dihydroxyvitamin D3 [1,25(OH)2D3] axis and IGF-I in rats, using pamidronate to block resorption that normally contributes to mineral homeostasis. We fed 6-month-old Sprague Dawley female rats isocaloric diets containing 2.5% or 15% casein for 2 wk. Pamidronate was then administered sc (0.6 mg/kg/) for 5 d. Blood samples were collected at different time points. Serum 1,25(OH)2D3, IGF-I, PTH, calcium, and phosphorus were determined in all rats; vertebral bone strength and histomorphometric analysis were performed in rats subject to the longest low-protein diets. We found 2 wk of low protein increased PTH levels, decreased 1,25(OH)2D3, calcium, and IGF-I, suggesting that increased PTH compensates for low-protein-induced decreases in 1,25(OH)2D3. Pamidronate augmented the increased PTH after 8 wk of low protein and prevented the 1,25(OH)2D3 decrease. IGF-I remained low. Protein malnutrition induced decreases in relative bone volume and trabecular thickness, which was prevented by pamidronate. Maximal load was reduced by protein restriction, but rescued by pamidronate. In summary, the low protein diet resulted in hyperparathyroidism, a reduction in circulating levels of IGF-I, and reduced 1,25(OH)2D3 despite hyperparathyroidism. Blocking resorption resulted in further increases in PTH and improved microarchitecture and biomechanical properties, irrespective of vitamin D status or protein intake.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joanna Moro ◽  
Catherine Chaumontet ◽  
Patrick C. Even ◽  
Anne Blais ◽  
Julien Piedcoq ◽  
...  

AbstractTo study, in young growing rats, the consequences of different levels of dietary protein deficiency on food intake, body weight, body composition, and energy balance and to assess the role of FGF21 in the adaptation to a low protein diet. Thirty-six weanling rats were fed diets containing 3%, 5%, 8%, 12%, 15% and 20% protein for three weeks. Body weight, food intake, energy expenditure and metabolic parameters were followed throughout this period. The very low-protein diets (3% and 5%) induced a large decrease in body weight gain and an increase in energy intake relative to body mass. No gain in fat mass was observed because energy expenditure increased in proportion to energy intake. As expected, Fgf21 expression in the liver and plasma FGF21 increased with low-protein diets, but Fgf21 expression in the hypothalamus decreased. Under low protein diets (3% and 5%), the increase in liver Fgf21 and the decrease of Fgf21 in the hypothalamus induced an increase in energy expenditure and the decrease in the satiety signal responsible for hyperphagia. Our results highlight that when dietary protein decreases below 8%, the liver detects the low protein diet and responds by activating synthesis and secretion of FGF21 in order to activate an endocrine signal that induces metabolic adaptation. The hypothalamus, in comparison, responds to protein deficiency when dietary protein decreases below 5%.


1973 ◽  
Vol 45 (s1) ◽  
pp. 99s-102s
Author(s):  
Hideo Ueda

1. High-salt, high-carbohydrate and low-protein diet induces remarkable elevation of blood pressure in spontaneous hypertensive rats (SHR). 2. These animals have low serum potassium, low blood urea nitrogen and high blood sugar. 3. Heart weight is increased in proportion to the elevation of blood pressure. 4. Kidney weight of rats receiving the high-salt, high-carbohydrate and low-protein diet was, by contrast, smaller than SHR receiving a normal diet. 5. The kidneys of SHR receiving a high-salt, high-protein diet were twice as heavy as the kidneys of normal rats. 6. Similar dietary modifications in Goldblatt hypertensive rats to those in SHR produced similar changes in blood pressure and heart weight.


Nephron ◽  
1998 ◽  
Vol 79 (2) ◽  
pp. 173-180 ◽  
Author(s):  
N. Soroka ◽  
D.S. Silverberg ◽  
M. Greemland ◽  
Y. Birk ◽  
M. Blum ◽  
...  

1995 ◽  
Vol 6 (5) ◽  
pp. 1379-1385
Author(s):  
J Coresh ◽  
M Walser ◽  
S Hill

Concerns have been raised about the possibility of protein restriction resulting in malnutrition and poor subsequent survival on dialysis. However, no studies have examined patients treated with protein restriction to determine their subsequent survival on dialysis. This study prospectively monitored 67 patients with established chronic renal failure (mean initial serum creatinine of 4.3 mg/dL) who were treated with a very low-protein diet (0.3 g/kg per day) supplemented with either essential amino acids or a ketoacid-amino acid mixture and observed closely for clinical complications. Forty-four patients required dialysis. Once dialysis was started, dietary treatment was no longer prescribed. The cumulative mortality rate during the first 2 yr after starting dialysis was 7% (95% confidence interval, 0 to 16%). During this period, only two deaths occurred compared with 11.5 deaths expected on the basis of national mortality rates adjusted for age, sex, race, and cause of renal disease (P = 0.002). However, the protective effect was limited to the first 2 yr on dialysis. Thereafter, mortality rates increased, resulting in a total of 10 deaths during 96.4 person-years of follow-up, which was not significantly lower than the 14.9 deaths expected (P = 0.25). Extrapolation of sequential serum creatinine measurements made before dietary treatment suggests that the improved survival cannot be due to the early initiation of dialysis. Although the lack of an internal control group and data on dialysis lends uncertainty, the large difference in mortality rate between these patients and the nationwide experience indicates that protein restriction and close clinical monitoring predialysis does not worsen and may substantially improve survival during the first 2 yr on dialysis. These findings point out the importance of studying predialysis treatments as a means for lowering mortality on dialysis.


1999 ◽  
Vol 81 (2) ◽  
pp. 145-152 ◽  
Author(s):  
Myriam Sanchez-Gomez ◽  
Kjell Malmlöf ◽  
Wilson Mejia ◽  
Antonio Bermudez ◽  
Maria Teresa Ochoa ◽  
...  

The aim of the present study was to investigate the influence of dietary protein level on the protein anabolic effects of growth hormone (GH) and insulin-like growth factor-I (IGF-I). Female growing rats were fed on either a high- or a low-protein diet with crude protein contents of 222 and 83 g/kg respectively. The diets contained the same amount of metabolizable energy (15·1 MJ/kg) and were given during a 14 d period. During the same time, three groups of rats (n 8) on each diet received subcutaneous infusions of either saline, recombinant human GH (rhGH) or recombinant human IGF-I (rhIGF-I). rhGH and rhIGF-I were given in doses of 360 and 500 μg/d respectively. The low-protein diet alone reduced significantly (P < 0·05) IGF-I concentrations in serum and in tissue taken from the gastrocnemius muscle as well as IGF-I mRNA from the same muscle. The responses to rhGH and rhIGF-I in terms of muscle IGF-I and its mRNA were variable. However, when rhIGF-I was infused into rats on the high-protein diet, significantly elevated levels of IGF-I in muscle tissues could be observed. This was associated with a significantly (P < 0·05) increased N balance, whereas rhGH significantly (P < 0·05) enhanced the N balance in rats on the low-protein diet. Thus, it can be concluded that the level of dietary protein ingested regulates not only the effect of IGF-I on whole-body N economy but also the regulation of IGF-I gene expression in muscles. The exact mechanism by which GH exerts its protein anabolic effect, however, remains to be elucidated.


1995 ◽  
Vol 88 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Tsukasa Nakamura ◽  
Mitsumine Fukui ◽  
Isao Ebihara ◽  
Shiori Osada ◽  
Toshimasa Takahashi ◽  
...  

1. The present study was designed to assess whether glomerular expression of mRNAs for endothelin-1 and endothelin-3, as well as endothelin receptors A and B is affected by a low-protein diet during the course of focal glomerular sclerosis. 2. Focal glomerular sclerosis was induced in rats by injection of puromycin aminonucleoside on days 0, 27, 34 and 41 in conjunction with unilateral nephrectomy on day 22. Control rats were subjected to nephrectomy or sham operation on day 22. 3. Animals were divided into six groups. In group 1, the puromycin aminonucleoside-injected rats were fed a standard diet containing 22% protein. In group 2, the puromycin aminonucleoside-injected rats were fed a low-protein diet containing 6% protein, which was initiated on the day of the first puromycin aminonucleoside injection. In group 3, the nephrectomized rats without puromycin aminonucleoside were fed a standard diet. In group 4, the nephrectomized rats without puromycin aminonucleoside were fed a low-protein diet. In group 5, the sham-operated rats were fed a standard diet. In group 6, the sham-operated rats were fed a low-protein diet. 4. The percentage of sclerotic glomeruli in group 1 rats increased markedly with time, reaching 77% on day 80. 5. The glomerular mRNA levels for endothelin-1 and endothelin receptors A and B increased significantly as glomerular sclerosis progressed, whereas no endothelin-3 mRNA was detected in the glomeruli of any group. 6. The endothelin-1 production in isolated glomeruli from group 1 increased significantly as glomerular sclerosis progressed. 7. In group 2, the low-protein diet reduced the prevalence of glomerular sclerosis, attenuated the rise in mRNA levels for endothelin-1 and endothelin receptors A and B and reduced endothelin-1 production in glomeruli from rats with focal glomerular sclerosis. 8. These data indicate that increases in glomerular endothelin-1 and endothelin receptor mRNA levels are associated with the development of puromycin aminonucleoside-induced glomerular sclerosis. These effects are blunted by administration of a low-protein diet.


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