Immunohistochemical detection of changes in growth hormone cells in rat pituitaries in protein deficiency

1975 ◽  
Vol 33 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Therese Drummond
Keyword(s):  
Growth Hormone ◽  
Normal Diet ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Immunohistochemical Method ◽  
Deficient Diet ◽  
Low Protein ◽  
Gh Cells ◽  
Protein Free Diet ◽  
Cell Changes

1. An immunohistochemical method was used to study the effect of a low-protein diet on growth hormone (GH) cells in the pituitaries of developing rats. The deficient diet (80 g protein/kg) was administered during gestation and lactation, or during the time after weaning until 90 d of age, or during both periods.2. GH-cell changes were much more striking in males than in females.3. In males, GH-producing cells were usually reduced in size and number in all treatments. The effect was most intense when protein deprivation occurred throughout gestation and sucking, and continued until 90 d of age, but it was also evident in animals given the low protein diet only after weaning. Recuperation appeared to be almost complete when offspring of deprived dams were fed on a normal diet after weaning.4. It is concluded that a low-protein diet reduces the amount of GH in the rat pituitary in a way similar to that with a protein-free diet.

Effect of High-Salt, High-Carbohydrate, Low-Protein Diet on Hypertension in the Rat

1973 ◽  
Vol 45 (s1) ◽  
pp. 99s-102s
Author(s):  
Hideo Ueda
Keyword(s):  
Blood Pressure ◽  
High Protein Diet ◽  
Normal Diet ◽  
High Salt ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Heart Weight ◽  
Hypertensive Rats ◽  
High Carbohydrate ◽  
Low Protein

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.

scholarly journals Insulin-like growth factor-I, but not growth hormone, is dependent on a high protein intake to increase nitrogen balance in the rat

1999 ◽  
Vol 81 (2) ◽  
pp. 145-152 ◽  
Author(s):  
Myriam Sanchez-Gomez ◽  
Kjell Malmlöf ◽  
Wilson Mejia ◽  
Antonio Bermudez ◽  
Maria Teresa Ochoa ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Dietary Protein ◽  
Protein Diet ◽  
N Balance ◽  
Low Protein Diet ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Low Protein ◽  
Igf I

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.

VITAMIN A AND CAROTENE UTILIZATION IN PROTEIN-DEPRIVED RATS

1963 ◽  
Vol 41 (1) ◽  
pp. 543-549 ◽  
Author(s):  
J. Mathews ◽  
G. H. Beaton
Keyword(s):  
Vitamin A ◽  
Serum Vitamin ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Separate Study ◽  
Casein Diet ◽  
Significant Lowering ◽  
Low Protein ◽  
Protein Free Diet ◽  
Β Carotene

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.

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

Increased NaCl preference of rats fed low-protein diet

1996 ◽  
Vol 270 (6) ◽  
pp. R1189-R1196 ◽  
Author(s):  
A. Okiyama ◽  
K. Torii ◽  
M. G. Tordoff
Keyword(s):  
Control Diet ◽  
Physiological Mechanism ◽  
Plasma Renin ◽  
Calcium Deficiency ◽  
Protein Deficiency ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Sodium Balance ◽  
Deficient Diet ◽  
Low Protein

Four studies were conducted to assess the effect of a low-protein diet on NaCl intake. Young rats fed either control (20% casein) or low-protein (5% casein) high-carbohydrate (CHO) diet were allowed to drink either water alone or water and 300 mM NaCl. Relative to rats fed control diet, rats fed the low-protein diet progressively increased NaCl intake so that, despite lower food and water intakes, they drank 180% more NaCl during the last 3 days of the 21-day test. Additional studies found that rats fed low-protein diet always maintained positive sodium balance, were neither sodium depleted nor hypovolemic, and had normal plasma renin activity and aldosterone concentrations. The elevated NaCl intake was not secondary to calcium deficiency and was unaffected by mineral supplementation of the protein-deficient diet. Increases in the diet's CH and/or fat content incidental to decreases in its protein content influenced, but could not completely account for, the effect of protein deficiency on NaCl intake. We conclude that protein deficiency is the primary cause of the elevated NaCl preference produced by being fed a low-protein diet and that a novel physiological mechanism underlies this behavior.

INSULIN HYPERPHAGIA IN RATS FED A LOW-PROTEIN DIET

1965 ◽  
Vol 43 (2) ◽  
pp. 225-233 ◽  
Author(s):  
J. R. Beaton ◽  
V. Feleki ◽  
J. A. F. Stevenson
Keyword(s):  
Food Intake ◽  
Body Fat ◽  
Normal Diet ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Eating Pattern ◽  
Low Protein ◽  
Running Activity ◽  
Male Wistar Rats ◽  
Rebound Increase

This investigation was undertaken to ascertain if daily treatment with insulin, known to increase lipogenesis, fat deposition, and food intake on a normal diet, could overcome or prevent, the hypophagia of rats fed a low-protein (5% casein) diet. Male Wistar rats on 20 or 5% casein diets were injected subcutaneously daily for 25 days with 2 units/100 g body weight of protamine zinc insulin (PZI) or saline. PZI increased the food intake and weight gain on both diets but not linear growth. It increased body fat markedly and protein slightly on the low-protein diet and body fat only on the normal diet. In a second similar experiment, in which treatment was continued for 17 days, PZI caused no change in resting oxygen consumption from that of the controls on either diet but did prevent the increase in running activity that rats on a low-protein diet show. In both experiments, although the insulin-treated rats on low-protein diet ate as many calories as the saline-treated controls on the normal diet, they gained significantly less weight. This paradox remains unexplained.The rebound increase in blood sugar following injection of PZI was relatively much faster in the low-protein animals. This was associated with a more immediate and greater food intake suggesting a "meal-eating" pattern of food intake in these animals which may have also enhanced lipogenesis.

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 The regulation of protein synthesis in the liver of rats. Mechanisms of dietary amino acid control in the immature animal

1968 ◽  
Vol 107 (5) ◽  
pp. 615-623 ◽  
Author(s):  
R. W. Wannemacher ◽  
W. K. Cooper ◽  
M. B. Yatvin
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Specific Radioactivity ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Deficient Diet ◽  
Low Protein ◽  
Rna Content ◽  
Cytoplasmic Rna

Weanling (23-day-old) rats were fed either on an amino acid-deficient diet (6% of casein, which in effect represents an ‘amino acid-deficient’ diet) or on a diet containing an adequate amount of protein (18% of casein) for 28 days. The hepatic cells from the animals fed on the low-protein diet were characterized by low amino acid content, almost complete inhibition of cell proliferation and a marked decrease in cell volume, protein content and concentration of cytoplasmic RNA compared with cells from control rats. The lower concentration of cytoplasmic RNA was correlated with a decreased ribosomal-RNA content, of which a larger proportion was in the form of free ribosomes. The protein-synthetic competence and messenger-RNA content of isolated ribosomes from liver cells of protein-deprived animals were 40–50% of those noted in controls. At 1hr. after an injection of radioactive uridine, the specific radioactivity of liver total RNA was greater in the group fed on the low-protein diet, but the amount of label that was associated with cytoplasmic RNA or ribosomes was significantly less than that noted in control animals. From these data it was concluded that dietary amino acids regulate hepatic protein synthesis (1) by affecting the ability of polyribosomes to synthesize protein and (2) by influencing the concentration of cytoplasmic ribosomes. It is also tentatively hypothesized that the former process may be directly related to the concentration of cellular free amino acids, whereas the latter could be correlated with the ability of newly synthesized ribosomal sub-units to leave the nucleus.

Low-Protein Diet Suppresses Serum Insulin-Like Growth Factor-1 and Decelerates the Progression of Growth Hormone-Induced Glomerulosclerosis

2001 ◽  
Vol 21 (4) ◽  
pp. 331-339 ◽  
Author(s):  
Sonia Q. Doi ◽  
Suvi Rasaiah ◽  
Ivan Tack ◽  
Jagannatha Mysore ◽  
John J. Kopchick ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Serum Insulin ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Insulin Like Growth Factor ◽  
Low Protein
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