Effects of low-protein diet on the pancreatic endocrine function of newborn and adult rats

Pancreatic islets were isolated from rats that had been nursed by dams fed with a control or an 8·7 % protein diet during the first 12 d of the lactation period. Glucose-induced insulin secretion from islets in the 8·7 % protein group was reduced 50 %. The islet insulin and DNA content were similar, whereas the pancreatic insulin content was reduced by 30 % in the rats fed 8·7 % protein. In order to elucidate the mechanism responsible for the attenuation of insulin secretion, measurements were performed of the activity of several islet enzymes that had previously been supposed to be involved in the coupling of glucose stimulation to insulin secretion. Islet glucose oxidation was unaffected, but glucose-stimulated hydrolysis of phosphatidylinositol was reduced by one-third in the islets of rats fed 8·7 % protein. The activity of mitochondrial glycerophosphate dehydrogenase was similar in islets of rats fed the 8·7 % protein diet and those fed the control diet. The activity of Ca-independent phospholipase A2was increased fourfold in the islets of rats fed 8·7 % protein. It is concluded that impairment of glucose-induced insulin secretion in rats fed a low-protein diet may be caused by attenuation of islet phosphatidylinositol hydrolysis, and it is tentatively suggested that the increased activity of Ca-independent phospholipase A2in islets of rats fed a low-protein diet may participate in the stimulation of apoptosis.

Download Full-text

Effect of prenatal programming and postnatal rearing on glomerular filtration rate in adult rats

AJP Renal Physiology ◽

10.1152/ajprenal.00593.2014 ◽

2015 ◽

Vol 308 (5) ◽

pp. F411-F419 ◽

Cited By ~ 13

Author(s):

German Lozano ◽

Ayah Elmaghrabi ◽

Jordan Salley ◽

Khurrum Siddique ◽

Jyothsna Gattineni ◽

...

Keyword(s):

Glomerular Filtration Rate ◽

Glomerular Filtration ◽

Filtration Rate ◽

Protein Diet ◽

Low Protein Diet ◽

Control Group ◽

Adult Rats ◽

Pregnant Rats ◽

Mature Adult ◽

Low Protein

The present study examined whether a prenatal low-protein diet programs a decrease in glomerular filtration rate (GFR) and an increase in systolic blood pressure (BP). In addition, we examined whether altering the postnatal nutritional environment of nursing neonatal rats affected GFR and BP when rats were studied as adults. Pregnant rats were fed a normal (20%) protein diet or a low-protein diet (6%) during the last half of pregnancy until birth, when rats were fed a 20% protein diet. Mature adult rats from the prenatal low-protein group had systolic hypertension and a GFR of 0.38 ± 0.03 versus 0.57 ± 0.05 ml·min−1·100 g body wt−1 in the 20% group ( P < 0.01). In cross-fostering experiments, mothers continued on the same prenatal diet until weaning. Prenatal 6% protein rats cross-fostered to a 20% mother on day 1 of life had a GFR of 0.53 ± 0.05 ml·min−1·100 g body wt−1, which was not different than the 20% group cross-fostered to a different 20% mother (0.45 ± 0.04 ml·min−1·100 g body wt−1). BP in the 6% to 20% group was comparable with the 20% to 20% group. Offspring of rats fed either 20% or 6% protein diets during pregnancy and cross-fostered to a 6% mother had elevated BP but a comparable GFR normalized to body weight as the 20% to 20% control group. Thus, a prenatal low-protein diet causes hypertension and a reduction in GFR in mature adult offspring, which can be modified by postnatal rearing.

Download Full-text

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

Nutrition and Health ◽

10.1177/0260106019900731 ◽

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.

Download Full-text

Effects of a Moderate Physical Training on the Leptin Synthesis by Adipose Tissue of Adult Rats Submitted to a Perinatal Low-protein Diet

Hormone and Metabolic Research ◽

10.1055/s-0032-1316350 ◽

2012 ◽

Vol 44 (11) ◽

pp. 814-818 ◽

Cited By ~ 6

Author(s):

I.H. de Mélo Montenegro ◽

L. Moita ◽

F.K. dos Reis ◽

E. de Oliveira ◽

P. Lisboa ◽

...

Keyword(s):

Adipose Tissue ◽

Physical Training ◽

Protein Diet ◽

Low Protein Diet ◽

Adult Rats ◽

Low Protein

Download Full-text

Kinetics of pyrimethamine in young and adult rats on a standard diet and on a low-protein diet

European Journal of Drug Metabolism and Pharmacokinetics ◽

10.1007/bf03191170 ◽

2009 ◽

Vol 34 (3-4) ◽

pp. 173-176 ◽

Cited By ~ 1

Author(s):

J. B. Mouankie ◽

W. Senczuk ◽

E. Florek

Keyword(s):

Protein Diet ◽

Low Protein Diet ◽

Standard Diet ◽

Adult Rats ◽

Low Protein ◽

Kinetics Of

Download Full-text

Nutritional recovery from a low-protein diet during pregnancy does not restore the kinetics of insulin secretion and Ca2+ or alterations in the cAMP/PKA and PLC/PKC pathways in islets from adult rats

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2017-0629 ◽

2018 ◽

Vol 43 (12) ◽

pp. 1257-1267

Author(s):

Leonardo Marin ◽

Hellen Barbosa Faria Silva ◽

Gabriela Damin ◽

Letícia Martins Ignacio-Souza ◽

Sílvia Regina de Lima Reis ◽

...

Keyword(s):

Insulin Secretion ◽

Protein Kinase ◽

Insulin Release ◽

Protein Diet ◽

Low Protein Diet ◽

Second Phase ◽

Adult Rats ◽

Low Protein ◽

Nutritional Recovery ◽

Kinetics Of

We investigated the insulin release induced by glucose, the Ca2+ oscillatory pattern, and the cyclic AMP (cAMP)/protein kinase A (PKA) and phospholipase C (PLC)/protein kinase C (PKC) pathways in islets from adult rats that were reared under diets with 17% protein (C) or 6% protein (LP) during gestation, suckling, and after weaning and in rats receiving diets with 6% protein during gestation and 17% protein after birth (R). First-phase glucose-induced insulin secretion was reduced in LP and R islets, and the second phase was partially restored in the R group. Glucose stimulation did not modify intracellular Ca2+ concentration, but it reduced the Ca2+ oscillatory frequency in the R group compared with the C group. Intracellular cAMP concentration was higher and PKA-Cα expression was lower in the R and LP groups compared with the C group. The PKCα content in islets from R rats was lower than that in C and LP rats. Thus, nutritional recovery from a low-protein diet during fetal life did not repair the kinetics of insulin release, impaired Ca2+ handling, and altered the cAMP/PKA and PLC/PKC pathways.

Download Full-text