scholarly journals The growth and development of rats given a low-protein diet

1972 ◽  
Vol 27 (3) ◽  
pp. 527-536 ◽  
Author(s):  
J. W. T. Dickerson ◽  
P. C. R. Hughes ◽  
P. A. McAnulty

1. Weanling (24-d-old) rats of a black and white hooded strain were allowed free access for 28 d to a diet containing 5% casein supplemented with methionine, and sucrose as the carbohydrate. Controls were fed on a 25% casein diet with a corresponding reduction in sucrose. Animals given the deficient diet were killed either at 52 d of age or after subsequent rehabilitation on the 25% casein diet when aged 140 d. These animals were compared with controls killed at these two ages and at the start of the experiment.2. The skeletons were X-rayed, skeletal maturity was determined according to a scoring system, and various bones were measured. The forebrain and cerebellum were analysed for cholesterol and DNA and the brain stem for cholesterol only. The DNA content of the paired quadriceps muscles and the livers was also determined.3. On the low-protein diet the body-weight rose by 7 g compared with the control value of 115 g. On rehabilitation, the body-weight of the previously malnourished group showed the expected growth spurt, but failed to attain that of the controls at 140 d.4. With the exception of the pelvis width, all the bones grew a little during the period on the low-protein diet. After rehabilitation, the hind limb, pelvis, iliac and spine lengths and the bi-iliac width remained smaller than these measurements in the corresponding controls, whereas there was no difference in the length of the fore limb, width of the pelvis or in the bone maturity score.5. The forebrains and cerebellums of the malnourished rats did not increase in weight, whereas some increase occurred in the brain stem. The concentration of cholesterol in the forebrains of the deficient animals was the same as that in controls of the same age, but on rehabilitation the concentration did not rise to the control value. The concentration of cholesterol in the cerebellum and brain stem of the deficient rats was lower than in controls of the same age but, whereas that in the cerebellum attained an almost normal level on rehabilitation, that in the brain stem remained significantly lower. The low-protein diet prevented the normal increase in cerebellum DNA and the amount remained low in the rehabilitated animals.6. The experimental diet caused a complete cessation of growth of the quadriceps muscles, and even after rehabilitation they weighed less than their controls. The DNA content, however, was not significantly lower.7. The low-protein diet did not permanently affect either the weight or DNA content of the liver.

2020 ◽  
Vol 26 (1) ◽  
pp. 53-64
Author(s):  
Peter Kelechi Ajuogu ◽  
Mohammed AK Al-Aqbi ◽  
Robert A Hart ◽  
Mitchell Wolden ◽  
Neil A Smart ◽  
...  

Background: Studies have shown that the amount of protein in the diet affects the hypothalamic-pituitary-testis axis and sub-optimal quantity reduces male fertility potential in both animals and humans. However, individual research reports on the factors associated with male infertility are collectively uncharacterized. Aim: We systematically reviewed, and meta-analysed animal (rats) studies on the effect of low protein diet on factors associated with male infertility. Methods: PubMed Central, EMBASE and Scopus databases were searched from inception to 30 March 2019 for the study concepts and related keywords in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Data on the outcome measures were extracted and pooled across trials using random-effects model and expressed as mean differences (MD) at a 95% confidence interval (CI). Results: Twelve trials identified from 3327 studies, met our inclusion criteria in the comparison of a low protein diet (2–10% protein) vs control protein diet (17–23% protein). The results showed that a low protein diet caused a significant reduction in the body weight ( P = 0.0001) testis weight ( P = 0.0001), seminal vesicle weight ( P = 0.0003), epididymis weight P = 0.02), serum testosterone ( P = 0.001) and follicle-stimulating hormone (FSH) concentrations ( P = 0.04) compared with the control treatments. No effect on luteinizing hormone (LH) plasma concentration ( P = 0.13) was observed. Conclusion: This study revealed that low protein diet caused significant reductions in body weight, testis, epididymis and seminal vesicle weights, serum testosterone and FSH concentration in rats. We infer that sub-optimal protein consumption reduces the gonadal and endocrine function, and consequently male infertility.


1963 ◽  
Vol 41 (1) ◽  
pp. 543-549 ◽  
Author(s):  
J. Mathews ◽  
G. H. Beaton

Maintenance of rats on a protein-free, but not a 4% casein, diet produced a significant lowering of serum vitamin A. This effect was seen in rats deprived of vitamin A or provided with 90 μg of the vitamin twice weekly. In a separate study, rats maintained on 4% and 20% casein diets were depleted of vitamin A. They were then given 6 or 12 μg of vitamin A or 24 μg of carotene per day. The blood vitamin A response to administered vitamin A was not affected. Rats fed the low-protein diet exhibited only about one half of the serum vitamin A response to administered carotene as did those fed the 20% casein diet. Carotene failed to maintain liver vitamin A content in rats fed the low-protein diet. The results suggested that the absorption/conversion of β-carotene is impaired in rats maintained on a 4% protein diet. When rats were fed a protein-free diet the mobilization of vitamin A from the liver, or transport of the vitamin was also impaired.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Hideaki Sato ◽  
Masako Tsukamoto-Yasui ◽  
Satoko Ueno ◽  
Keiko Matsunaga ◽  
Akihiko Kitamura

Abstract Objectives Increase of elderly people, dementia and cognitive decline has been already one of the social problems all over the world. There are a lot of risk factors including dietary composition. Several studies have reported the importance of protein for maintaining brain functions in the elderly, but the details are not well understood. To clarify the relationship between protein intake and brain function in the elderly, we evaluated the effect of low protein diet on cognitive function and psychiatric symptoms in aged mice. Methods Male mice at 60 weeks of age were fed a control diet (NPD; casein 20%) or a low protein diet (LPD; casein 5%). To evaluate neurobehavioral abnormality, we performed the elevated plus maze task (Day 64) and Passive avoidance task (conditioning: Day 66, evaluation: Day 67). Cerebral cortex tissues and plasma were measured for free amino acid concentration by LC-MSMS method, and monoamine concentration in cerebral cortex was measured by HPLC method. Results In the Passive avoidance task, LPD group decreased the time to keep staying in the light box and the rate of individuals entering the dark box during the test period. In the elevated plus maze task, LPD group significantly increased in the number of entry and staying times in open arm. In addition, total travel distance was significantly increased. Moreover, LPD decreased the concentration of not only amino acid in plasma and cerebral cortex but also neurotransmitter such as Glutamate, GABA, Aspartate, Glycine, Dopamine, Norepinephrine, Serotonin. Conclusions We found that long-term intake of low-protein diet occurred memory loss and anxiety like behavior in elderly mice. Intracerebral neurotransmitters are mainly synthesized from amino acids, which is transferred from blood, within the brain. Therefore, behavioral change observed in LPD group might be induced by the decrease of neurotransmitters in the brain. Funding Sources Ajinomoto Co., Inc.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Daniel Tomé ◽  
Joanna Moro ◽  
Anne Blais ◽  
Catherine Chaumontet ◽  
Patrick Even ◽  
...  

Abstract Objectives Low protein diet and essential amino acid deficient-diet have an impact on body weight and growth and different studies also showed an impact of lysine intake on bone metabolism. Lysine has been shown to promote the absorption of intestinal calcium and to participate in the collagen synthesis through its involvement in the reticulation process of the tropocollagen beams. The assembly of tropocollagen bundle into mature collagen fibers is essential for bone formation and remodeling (civitelli et al, 1992; Fini et al, 2001). The objective of this study was to characterize the impact of low protein diet and lysine-deficient diet on bone metabolism of growing rats. Methods Study 1: 6 group of growing rats were fed for 3 weeks different diet with different content of milk protein at levels of 3%, 5%, 8%, 12%, 15% or 20% (% total energy). Study 2: 7 group of growing rats were fed diets with different lysine content (as % of lysine requirement), for 3 weeks: 15%, 25%, 40%, 60%, 75%, 100% or 170% (% Lysine requirement). Body weight was measured daily. At the end of the experiment, the body composition was analyzed and tissues were removed for measurements of the expression of genes involved in protein and bone metabolism. Statistical analysis was done by variance analysis. Results Rats fed low protein diet (3% and 5% of milk protein), compared to control have a lower growth, with a lower body weight and naso-anal length. This weak growth was associated with a lower lean body mass, and also had an impact on bone metabolism. There was a decrease in the bone mineral density, bone mineral content and femur size, associated with a decrease of markers of bone turnover and formation. The same results on bone metabolism were observed on rats fed the 85% lysine deficient diet. Conclusions Low protein diet and lysine-deficient diet reduce growth and bone metabolism. The impact of low protein diet could be related to the lysine deficiency, which have an impact on the calcium intestinal absorption and on collagen synthesis. Funding Sources INRA, AgroParisTech. Supporting Tables, Images and/or Graphs


1980 ◽  
Vol 94 (3) ◽  
pp. 321-326 ◽  
Author(s):  
Kazue Takano ◽  
Naomi Hizuka ◽  
Kazuo Shizume ◽  
Yoko Hasumi ◽  
Toshio Tsushima

Abstract. Serum somatomedin A was significantly reduced after 3 days of fasting in rats with a mean decrease of 23.6 ± 2.4% (N = 18) of initial values. Re-feeding for one day produced a definite increase in somatomedin A, with a rise in body weight. When re-fed isocalorically for 21 days with diets of different quality, a low protein diet led to smaller increases in both seum somatomedin A and body weight in comparison to those of control-, high-protein- and high fat-diets (P < 0.001). There is a positive correlation between the increase in body weight and serum somatomedin A levels (N = 70, r = 0.71, P< 0.001). The effect of growth hormone on somatomedin generation was abolished in hypophysectomized rats fed with low-protein diet. Our study suggests that protein in the diet is important for the generation of somatomedin A, which is necessary for normal growth.


2014 ◽  
Vol 306 (10) ◽  
pp. H1444-H1452 ◽  
Author(s):  
Adam J. Watkins ◽  
Kevin D. Sinclair

Although the association between maternal periconceptional diet and adult offspring health is well characterised, our understanding of the impact of paternal nutrition at the time of conception on offspring phenotype remains poorly defined. Therefore, we determined the effect of a paternal preconception low protein diet (LPD) on adult offspring cardiovascular and metabolic health in mice. Male C57BL/6 mice were fed either normal protein diet (NPD; 18% casein) or LPD (9% casein) for 7 wk before mating. At birth, a reduced male-to-female ratio ( P = 0.03) and increased male offspring weight ( P = 0.009) were observed in litters from LPD compared with NPD stud males with no differences in mean litter size. LPD offspring were heavier than NPD offspring at 2 and 3 wk of age ( P < 0.02). However, no subsequent differences in body weight were observed. Adult male offspring derived from LPD studs developed relative hypotension (decreased by 9.2 mmHg) and elevated heart rate ( P < 0.05), whereas both male and female offspring displayed vascular dysfunction and impaired glucose tolerance relative to NPD offspring. At cull (24 wk), LPD males had elevated adiposity ( P = 0.04), reduced heart-to-body weight ratio ( P = 0.04), and elevated circulating TNF-α levels ( P = 0.015) compared with NPD males. Transcript expression in offspring heart and liver tissue was reduced for genes involved in calcium signaling ( Adcy, Plcb, Prkcb) and metabolism ( Fto) in LPD offspring ( P < 0.03). These novel data reveal the impact of suboptimal paternal nutrition on adult offspring cardiovascular and metabolic homeostasis, and provide some insight into the underlying regulatory mechanisms.


Author(s):  
Warid Khayata ◽  
Ahmad Kamri ◽  
Rasha Alsaleh

<p><strong>Objective: </strong>The aim of this work was to investigate the capability of a high dose of thaumatin; a sweet tasting protein, of improving induced protein malnutrition in male Wistar rats.</p><p><strong>Methods: </strong>For this study, 12 rats were divided into 2 groups and treated orally along with a high-carbohydrate, low-protein diet as follows: water group as a negative control, and thaumatin group at a dose of 464 mg/kg for 3 consecutive w. Blood samples were collected to analyse glucose, triglycerides, total cholesterol, and total protein, and body weight was measured. An oral glucose tolerance test (OGTT) was carried out at the end of the experiment.</p><p><strong>Results: </strong>Despite the high amount of<strong> </strong>thaumatin used, only a slight increase in blood glucose occurred and was within the normal range, whereas serum triglycerides and cholesterol decreased significantly unlike control. Body weight had declined in both groups due to a low-protein diet, while total protein and glucose tolerance remained unchanged.</p><strong>Conclusion: </strong>It is found that<strong> </strong>thaumatin is safe to consume by Wistar rats even at high doses. Besides that high-carbohydrate, low-protein diet caused falling of body weight, it had drawbacks of increased triglycerides and cholesterol levels which can be useful to create animal models of abnormal lipid metabolism without obesity. However, simultaneous ingestion of thaumatin with this diet had altered the outcomes to the best case. In future, it may be possible to use this combination for achieving healthy eating patterns without drug intervention that is needed for obese patients with various dysglycemia or dyslipidemia manifestations and people following regimes for weight reduction.<p> </p>


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Carol Góis Leandro ◽  
Marco Fidalgo ◽  
Adriano Bento-Santos ◽  
Filippe Falcão-Tebas ◽  
Diogo Vasconcelos ◽  
...  

The effects of pregestational and gestational low-to-moderate physical training on insulin secretion in undernourished mothers were evaluated. Virgin female Wistar rats were divided into four groups as follows: control (C,n=5); trained (T,n=5); low-protein diet (LP,n=5); trained with a low-protein diet (T + LP,n=5). Trained rats ran on a treadmill over a period of 4 weeks before mate (5 days week−1and 60 min day−1, at 65% ofVO2max). At pregnancy, the intensity and duration of the exercise were reduced. Low-protein groups were provided with an 8% casein diet, and controls were provided with a 17% casein diet. At third day after delivery, mothers and pups were killed and islets were isolated by collagenase digestion of pancreas and incubated for a further 1 h with medium containing 5.6 or 16.7 mM glucose. T mothers showed increased insulin secretion by isolated islets incubated with 16.7 mM glucose, whereas LP group showed reduced secretion of insulin by isolated islets when compared with both C and LP + T groups. Physical training before and during pregnancy attenuated the effects of a low-protein diet on the secretion of insulin, suggesting a potential role for compensation of insulin resistance and preventing gestationaldiabetes mellitus.


1967 ◽  
Vol 21 (2) ◽  
pp. 457-465 ◽  
Author(s):  
P. Schmida ◽  
Elise M. Widdowson

1. Rats 10 weeks old were fed for 9 weeks either on a stock diet containing 17% protein, or on a low-protein diet prepared from the stock diet with added glucose, minerals and vitamins. Half the animals on each diet were kept at room temperature (21°) and half in a cold environment (5°).2. The calorie intake of the animals kept at 5° on both diets was 60–70% higher than that of the corresponding group at 21°. The animals on the stock diet and kept at 5° gained weight but not so much as those on the same diet at 21°. The animals kept on the low-protein diet at 21° lost weight, while those on the same diet at 5° lost only a little weight initially and none thereafter.3. On both types of diet the liver, kidneys and gastro-intestinal tract weighed more per 100 g body-weight in animals kept in the colder of the two environments; the small intestine was conspicuous in this respect.4. The weight of the fur was greater, and the weight of the skin less per 100 g body-weight at 5° than at 21°.5. The animals on the stock diet at 21° had most fat in their bodies, both in absolute terms and per 100 g body-weight. There were no significant differences between the other three groups.6. The skin of the animals kept at 5° had a significantly higher collagen to N ratio than the skin of those having the same diet at 21°.


1992 ◽  
Vol 82 (2) ◽  
pp. 191-198 ◽  
Author(s):  
M. Langran ◽  
B. J. Moran ◽  
J. L. Murphy ◽  
A. A. Jackson

1. Urea kinetics were measured by using prime/intermittent oral doses of [15N15N]urea in five healthy men taking formula diets adequate in energy and containing either 70 or 35 g of protein/day. In some studies the low-protein diet was supplemented with non-starch polysaccharides in the form of ispaghula husk or ripe bananas. 2. On the 70 g of protein/day diet urea production was 132% of intake. Only 54% of the urea produced was excreted in the urine with 46% being salvaged in the colon; 90% of the salvaged nitrogen was retained in the metabolic nitrogen pool. 3. On the 35 g of protein/day diet the small decrease in urea production rate compared with that on the 70 g of protein/day diet was not significant, but only 36% of the urea produced was excreted in urine, with the majority, 64%, being salvaged. 4. The extent of urea-nitrogen salvaging on the 35 g of protein/day diet was similar in magnitude to the decrease in nitrogen intake, with the effect that the sum of intake and salvaged nitrogen did not differ between the 35 and the 70 g of protein/day diets. This implies that quantitative control is exerted over the rate at which urea nitrogen is salvaged. 5. The addition of non-starch polysaccharides to the 35 g of protein/day diet had a demonstrable effect upon faecal weight and composition, but did not exert any significant influence upon urea kinetics. 6. It is concluded that large changes in the rate of urea production are not necessary for adaptation to a low-protein diet, rather the salvaging of urea nitrogen in the lower bowel appears to be an important mechanism through which the body adapts to a low-protein diet. The salvaging of urea nitrogen by the colon makes an important contribution to the conservation of body nitrogen.


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