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

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.

2010 ◽  
Vol 15 (4) ◽  
pp. 262-266 ◽  
Author(s):  
Won-Hee Choi ◽  
Ji-Yun Ahn ◽  
Sun-A Kim ◽  
Tae-Wan Kim ◽  
Tae-Youl Ha

2006 ◽  
Vol 111 (4) ◽  
pp. 281-287 ◽  
Author(s):  
Michael R. Skilton ◽  
Alison K. Gosby ◽  
Ben J. Wu ◽  
Lisa M. L. Ho ◽  
Roland Stocker ◽  
...  

Epidemiological studies suggest a link between fetal/early infant nutrition and adult coronary artery disease. In the present study, we examined the effects of altering nutrition during gestation, lactation and juvenile life on aortic structure and function in rats. Wistar rat dams were fed either a control or low-protein diet throughout pregnancy, or a low-protein diet for the final 7 days of gestation only. At 21 days post-partum, male pups were weaned on to a control, low-protein or high-fat diet. At 12 weeks, the offspring rats were killed. In 46 rats, aortic sections were mounted and stained to assess media thickness and elastin content. In a further 38 rats, aortic rings were suspended in an organ bath and vascular reactivity was tested with dose–response curves to the endothelium-dependent dilator acetylcholine and the endothelium-independent dilator sodium nitroprusside. Rats exposed to maternal protein restriction while in utero had a significantly decreased aortic wall thickness compared with control rats (P=0.005). Total elastin content of the aorta was also decreased by both maternal low-protein (P=0.02) and early postnatal low-protein (P=0.01) diets. Neither maternal nor postnatal low-protein or high-fat diets, however, resulted in any significant changes in arterial dilator function. In conclusion, fetal undernutrition in rats, induced via a maternal low-protein diet, causes a decrease in aortic wall thickness and elastin content without altering aortic dilator function. These changes in vascular structure may amplify aging-related changes to the vasculature and contribute to the pathophysiology of the putative link between impaired fetal growth and adult cardiovascular disease.


2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Camila Lubaczeuski ◽  
Luciana Mateus Gonçalves ◽  
Jean Franciesco Vettorazzi ◽  
Mirian Ayumi Kurauti ◽  
Junia Carolina Santos-Silva ◽  
...  

The aim of this study was to investigate the effect of subdiaphragmatic vagotomy on insulin sensitivity, secretion, and degradation in metabolic programmed mice, induced by a low-protein diet early in life, followed by exposure to a high-fat diet in adulthood. Weaned 30-day-old C57Bl/6 mice were submitted to a low-protein diet (6% protein). After 4 weeks, the mice were distributed into three groups: LP group, which continued receiving a low-protein diet; LP + HF group, which started to receive a high-fat diet; and LP + HFvag group, which underwent vagotomy and also was kept at a high-fat diet. Glucose-stimulated insulin secretion (GSIS) in isolated islets, ipGTT, ipITT, in vivo insulin clearance, and liver expression of the insulin-degrading enzyme (IDE) was accessed. Vagotomy improved glucose tolerance and reduced insulin secretion but did not alter adiposity and insulin sensitivity in the LP + HFvag, compared with the LP + HF group. Improvement in glucose tolerance was accompanied by increased insulinemia, probably due to a diminished insulin clearance, as judged by the lower C-peptide : insulin ratio, during the ipGTT. Finally, vagotomy also reduced liver IDE expression in this group. In conclusion, when submitted to vagotomy, the metabolic programmed mice showed improved glucose tolerance, associated with an increase of plasma insulin concentration as a result of insulin clearance reduction, a phenomenon probably due to diminished liver IDE expression.


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.


2019 ◽  
Vol 34 (6) ◽  
pp. 1531-1546 ◽  
Author(s):  
Ravinder Naik Dharavath ◽  
Shiyana Arora ◽  
Mahendra Bishnoi ◽  
Kanthi Kiran Kondepudi ◽  
Kanwaljit Chopra

2014 ◽  
Vol 5 (3) ◽  
pp. 229-239 ◽  
Author(s):  
K. M. Platt ◽  
R. J. Charnigo ◽  
K. J. Pearson

Maternal high-fat diet consumption and obesity have been shown to program long-term obesity and lead to impaired glucose tolerance in offspring. Many rodent studies, however, use non-purified, cereal-based diets as the control for purified high-fat diets. In this study, primiparous ICR mice were fed purified control diet (10–11 kcal% from fat of lard or butter origin) and lard (45 or 60 kcal% fat) or butter (32 or 60 kcal% fat)-based high-fat diets for 4 weeks before mating, throughout pregnancy, and for 2 weeks of nursing. Before mating, female mice fed the 32 and 60% butter-based high-fat diets exhibited impaired glucose tolerance but those females fed the lard-based diets showed normal glucose disposal following a glucose challenge. High-fat diet consumption by female mice of all groups decreased lean to fat mass ratios during the 4th week of diet treatment compared with those mice consuming the 10–11% fat diets. All females were bred to male mice and pregnancy and offspring outcomes were monitored. The body weight of pups born to 45% lard-fed dams was significantly increased before weaning, but only female offspring born to 32% butter-fed dams exhibited long-term body weight increases. Offspring glucose tolerance and body composition were measured for at least 1 year. Minimal, if any, differences were observed in the offspring parameters. These results suggest that many variables should be considered when designing future high-fat diet feeding and maternal obesity studies in mice.


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


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