The effect of dietary protein intake on factors associated with male infertility: A systematic literature review and meta-analysis of animal clinical trials in rats

2020 ◽  
Vol 26 (1) ◽  
pp. 53-64
Author(s):  
Peter Kelechi Ajuogu ◽  
Mohammed AK Al-Aqbi ◽  
Robert A Hart ◽  
Mitchell Wolden ◽  
Neil A Smart ◽  
...  
Keyword(s):  
Body Weight ◽  
Male Infertility ◽  
Seminal Vesicle ◽  
Serum Testosterone ◽  
The Body ◽  
Protein Diet ◽  
Endocrine Function ◽  
Low Protein Diet ◽  
Factors Associated ◽  
Low Protein

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.

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
Keyword(s):  
Body Weight ◽  
Brain Stem ◽  
Dna Content ◽  
The Body ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Casein Diet ◽  
Control Value ◽  
Low Protein ◽  
The Brain

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.

scholarly journals Impact of Low Protein and Lysine-deficient Diets on Bone Metabolism (P08-072-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Daniel Tomé ◽  
Joanna Moro ◽  
Anne Blais ◽  
Catherine Chaumontet ◽  
Patrick Even ◽  
...  
Keyword(s):  
Body Weight ◽  
Bone Metabolism ◽  
Collagen Synthesis ◽  
Milk Protein ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Deficient Diet ◽  
Growing Rats ◽  
Low Protein ◽  
The Impact

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

Effect of nutrition on growth and somatomedin A levels in the rat

1980 ◽  
Vol 94 (3) ◽  
pp. 321-326 ◽  
Author(s):  
Kazue Takano ◽  
Naomi Hizuka ◽  
Kazuo Shizume ◽  
Yoko Hasumi ◽  
Toshio Tsushima
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Normal Growth ◽  
Protein Diet ◽  
Low Protein Diet ◽  
High Fat ◽  
Low Protein ◽  
High Fat Diets ◽  
Hypophysectomized Rats ◽  
Fat Diets

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.

scholarly journals Paternal low protein diet affects adult offspring cardiovascular and metabolic function in mice

2014 ◽  
Vol 306 (10) ◽  
pp. H1444-H1452 ◽  
Author(s):  
Adam J. Watkins ◽  
Kevin D. Sinclair
Keyword(s):  
Body Weight ◽  
Vascular Dysfunction ◽  
Weight Ratio ◽  
Male Offspring ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Adult Offspring ◽  
Female Ratio ◽  
Low Protein ◽  
The Impact

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.

scholarly journals Curcumin ameliorates atrophy of seminal vesicle via reduction of oxidative stress in castrated mice

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7192 ◽  
Author(s):  
Rui Li ◽  
Hao Li ◽  
Ke Rao ◽  
Kang Liu ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Body Weight ◽  
Seminal Vesicle ◽  
Serum Testosterone ◽  
The Body ◽  
Intragastric Administration ◽  
Curcumin Treatment ◽  
Seminal Vesicle Weight ◽  
High Level ◽  
And Function

Background The growth and function of seminal vesicle are dependent on androgen. This study was conducted to investigate the role of oxidative stress in castration-induced seminal vesicle atrophy and to explore the effects of curcumin, an antioxidant extracted from rhizome of turmeric, on seminal vesicle of castrated mice. Methods C57BL/6J mice were randomly divided into three groups: control, castration, and castration with curcumin (n = 10 for each group). After surgical castration, mice in the curcumin treatment group received intragastric administration of curcumin at 100 mg/kg body weight for 4 weeks, whereas mice in the other two groups were treated with olive oil. After that, the body weight, seminal vesicle weight and serum testosterone of mice were measured. Apoptosis and oxidative stress levels in seminal vesicle were also determined. Results After castration, both the weight and size of seminal vesicle decreased dramatically. The expression of three NADPH oxidase (NOX) subtypes: NOX1, NOX2 and NOX4, increased in seminal vesicle of castrated mice, resulting in high level oxidative stress. The ratio of Bax to Bcl-2 was also elevated after castration, accompanied by enhanced caspase3 activity. Additionally, castration increased the number of apoptotic cells in seminal vesicle. Curcumin treatment could inhibit the expression of NOX1, NOX2 and NOX4, decreasing oxidative stress and apoptosis. The atrophy of seminal vesicle caused by castration was ameliorated by curcumin. Conclusion Castration could cause atrophy of seminal vesicle probably via inducing oxidative stress. Curcumin treatment could reduce the oxidative stress in seminal vesicle by decreasing the expression of NOX1, NOX2 and NOX4, thereby ameliorating apoptosis and atrophy of seminal vesicle. Oxidative stress might play a role in castration-induced seminal vesicle atrophy.

scholarly journals BIOCHEMICAL EFFECT OF A HIGH DOSE OF THAUMATIN IN WISTAR RATS

2016 ◽  
Vol 9 (1) ◽  
pp. 304
Author(s):  
Warid Khayata ◽  
Ahmad Kamri ◽  
Rasha Alsaleh
Keyword(s):  
Body Weight ◽  
Glucose Tolerance ◽  
Total Protein ◽  
Wistar Rats ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Oral Glucose ◽  
High Dose ◽  
High Carbohydrate ◽  
Low Protein

<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>

scholarly journals The effect of a low-protein diet and a cold environment on calorie intake and body composition in the rat

1967 ◽  
Vol 21 (2) ◽  
pp. 457-465 ◽  
Author(s):  
P. Schmida ◽  
Elise M. Widdowson
Keyword(s):  
Body Weight ◽  
Room Temperature ◽  
Intestinal Tract ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Calorie Intake ◽  
Cold Environment ◽  
Stock Diet ◽  
Low Protein ◽  
Gastro Intestinal Tract

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°.

Adaptation to a diet low in protein: effect of complex carbohydrate upon urea kinetics in normal man

1992 ◽  
Vol 82 (2) ◽  
pp. 191-198 ◽  
Author(s):  
M. Langran ◽  
B. J. Moran ◽  
J. L. Murphy ◽  
A. A. Jackson
Keyword(s):  
The Body ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Urea Nitrogen ◽  
Low Protein ◽  
Urea Production ◽  
Urea Kinetics ◽  
Normal Man ◽  
Faecal Weight ◽  
Formula Diets

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.

scholarly journals THE EFFECT OF RESTRICTION OF PROTEIN INTAKE ON THE SERUM PROTEIN CONCENTRATION OF THE RAT

1933 ◽  
Vol 57 (5) ◽  
pp. 705-720 ◽  
Author(s):  
Arthur L. Bloomfield
Keyword(s):  
Body Weight ◽  
Serum Protein ◽  
Protein Intake ◽  
Protein Concentration ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Low Protein ◽  
Serum Protein Concentration

Rats placed on a low protein diet for 21 weeks, in spite of marked loss of body weight, showed no significant decrease of serum protein concentration aside from an initial (physiological ?) drop.

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