Effect Of Protein Deficiency Research Articles

RNA content and protein synthesis in skeletal muscles of young rats: effects of protein deficiency.

A protein-free diet was fed to weanling rats for 1, 2, 3, 4, or 7 days before sacrifice in order to determine the time course of RNA depletion from their gastrocnemius muscles. A 34% loss of total RNA occurred on the first 2 days and thereafter depletion occurred at approximately 8% per day. The time course of RNA repletion was determined by refeeding a stock diet to protein-starved rats. A significant increase in total RNA content occurred on the 2nd day and repletion of total RNA content was complete on the 4th day of refeeding the stock diet. Rates of muscle protein synthesis in vivo were estimated by 14C incorporation from L-leucine into muscle proteins, and correlations between RNA concentrations and rate of protein synthesis were evaluated by linear regression anlysis. There was no significant relationship between soluble RNA concentration and protein synthesis. The relationship between protein synthesis and microsomal RNA concentration was significant. The results support the conclusion that availability of ribosomal RNA is a major factor in the long-term regulation of muscle protein biosynthesis.

The effect of protein deficiency and calorie deficiency on the reproduction of rats.

1. Groups of twelve female rats were fed from 4 weeks of age on four different experimental dietary regimens, and on a stock diet containing 18% protein givenad lib.as a control (group 1). The rats in two of the experimental groups were malnourished either by being given a low-protein (9%) dietad lib.(group 2), or the stock diet containing 18% protein in limited amounts to maintain weight as in group 2. These animals were designated calorie-deficient (group 3). Two other groups of twelve rats were more severely malnourished from 4 to 13 weeks of age by being given a low-protein (6%) dietad lib.(group 4) or the stock diet in limited amounts to maintain weight as in group 4 (group 5). From 13 weeks all the rats in groups 4 and 5 were rehabilitated on stock dietad lib.2. Well-nourished males were introduced into the cages 1 week after the vaginas opened, and again immediately after the females had suckled successive litters. This was repeated until the females were 60 weeks old and had reared up to six litters.3. Chronic deprivation of protein or of calories delayed puberty, reduced fertility and gave rise to smaller numbers in the litters. It also interfered with lactation.4. More severe malnutrition for 9 weeks further delayed puberty, but when these animals were rehabilitated they produced as many young as those that had been well-nourished throughout. They lactated well and there was no carry-over of the effects of the early deficiencies.

Physiological effect of protein deficiency with special reference to evaluation of protein nutrition and protein requirement.

Physiological effect of protein deficiency with special reference to evaluation of protein nutrition and protein requirement.

Effect of protein deficiency on plasma progesterone levels during the menstrual cycle of adult rhesus monkeys.

Plasma progesterone levels in protein-deficient monkeys were determined by the competetive protein binding technique. The alternate day plasma samples from day 10 to the end of the menstrual cycle were analyzed. Of the 8 monkeys used, half were fed 20 % and the other half 10% protein diet (control diets) before the protein-deficient diet was provided. After a 6-month deficiency, all the monkeys were fed a 20% protein diet. On the control diets the monkeys showed a plasma progesterone rise on day 12, reaching a peak value of 5.5 ng/ml by the 18th day. These levels were maintained till day 20, when they gradually declined to 1 ng/ml before menstruation. During the deficient-diet feeding the monkeys showed a peak value of 2.4–4.0 ng/ml for the next 2–3 menstrual cycles. The cycles became shorter, the peak occurred a day earlier, and the progesterone level declined, sharply. Persistent low levels of progesterone were observed for the following 1–2 menstrual cycles, after which the monkeys had amenorrhea. Mens...

Protein Malnutrition in Children: Advances in Knowledge in the Last Ten Years

This chapter discusses the characteristics of protein malnutrition in children, with an emphasis on the biochemical and metabolic changes. It focuses on the nutritional processes, the study of which has been stimulated by disease protein malnutrition, and which have a wider relevance in medicine and biology. It is clear that in the last ten years a great deal of new knowledge has been gained about the effects of protein deficiency and protein-calorie imbalance in human beings. It is, however, more than ever apparent that the major problem is not treatment but prevention. Scientific interest is concentrated less on the acute and severe deficiency state, and more on the mild and marginal forms of protein malnutrition. These early stages can be recognized with more sensitive and specific biochemical measurements. The interpretation of the biochemical findings depends upon an understanding of the metabolic adjustments to different levels of protein intake. Only in this way it is possible to distinguish between the changes that are trivial and changes that are significant from the metabolic point of view.

Effect of Protein Deficiency during Gestation on Postnatal Cellular Development in the Young Rat

The effects of maternal protein deficit during pregnancy in rats on cell number and cell size in the organs of the progeny in the suckling period were studied. The effects of increased postnatal feeding of these progeny were also investigated. Pregnant rats were fed a diet containing 30% or 6% casein. Postnatally, young were suckled by nondeficient mothers in litters of eight until weaning or in litters which were cut to four young beginning at the age of 7 days. DNA, RNA, and total protein were determined in liver, kidney, heart, thymus, and brain of male young at 7, 14, and 21 days of age. Young of protein-deficient dams suckled in litters of eight had significantly decreased organ weights, DNA, total protein, and total RNA which persisted from birth but did not become more severe. When litters were cut to four in order to increase food intake, livers, kidneys, and hearts increased in weight and cells increased in size, but there were no significant changes in the numbers of cells in these organs. In the thymus, however, the number of cells increased, and cells decreased in size, while in the brain, the weight, DNA content, and apparent cell size were unaffected. The reduction of litter size had no effect on the deficit in cell population in any of the organs studied.

Some Effects of Protein Deficiency in Young Growing Pigs. III. Ferrokinetic Investigations

Ferrokinetic investigations have been carried out in pigs which had undergone protein starvation and rehabilitation. After long term protein deprivation haematocrit levels, blood haemoglobin levels, serum iron concentrations, serum total iron binding capacity and blood volume per kg body weight were all reduced in the deficient animals. The values for the rehabilitated animals were in the normal range. The erythrocytes of the protein starved pigs showed an increased rate of uptake of radioactive iron compared with the control pig. However, the turnover of iron as a whole was reduced greatly in the protein deprived group compared to the rehabilitated and control pigs. Accumulation of iron occurred in the livers, spleens and kidneys of the protein starved animals. The rehabilitated pigs had lower liver stores of iron than the control pig. On the basis of the data presented it has been concluded that these effects are mainly due to a shortage of amino acids for protein synthesis.

Some Effects of Protein Deficiency in Young Growing Pigs. II. Blood Plasma Free Amino Acids

The influence of protein deficiency, rehabilitation and total starvation on the free amino acid levels in the blood plasma of pigs has been investigated. It was found that the concentration of most amino acids was reduced during protein deficiency. The levels of leucine, isoleucine and valine were diminished by the greatest proportion, followed by threonine, tyrosine and citrulline. During the first few weeks of protein deficiency the levels of lysine, histidine and arginine were slightly increased, but later decreased below control values. Concentrations of glycine and alanine were altered in a similar way except that the initial increase was much more pronounced. The concentrations of most of these amino acids returned to control levels after rehabilitation. Total starvation led to an increase in concentration of leucine, isoleucine, valine, threonine and to a smaller extent phenylalanine, lysine, citrulline and arginine. The concentration of glycine, alanine and glutamic acid were very much reduced. The level of urea in the circulation dropped reversibly during protein deficiency and increased very much during total starvation.

Some Effects of Protein Deficiency in Young Growing Pigs

No significant differences between the serum protein concentrations of the totally starved pigs and control animals given a milk protein supplemented diet were found. Serum lipid levels rose in the totally starved group. During the first 42 days of the experimental period sharp falls in serum protein concentrations were noted in the protein deprived pigs. The losses were greatest in the albumin and two β-globulin fractions, γ-globulin levels rose but at a much slower rate than in the control group. In the pigs which were refed a protein containing diet during the second 42 day period, the concentrations of all the serum protein fractions except for γ-globulin had reached control levels by the end of the investigation. The pigs which continued with the protein free diet showed further losses of albumin, a reduction in some α-globulin fractions and a cessation of net γ-globulin synthesis. The trends observed by measurements of protein bound carbohydrate were similar to those obtained from polypeptide determinations indicating quantitative rather than qualitative changes in the serum proteins. The reduction in the serum lipid concentrations of the pigs undergoing protein starvation was largely accounted for by losses of α- and β-lipoproteins. The protein deprived pigs maintained their initial body weight, while a continuous fall in weight was found in the totally starved group and a continuous increase in the control pigs.

The effect of protein deficiency upon peritoneal healing and peritoneal wound contraction in the rat.

1. Adult rats were maintained on a protein-deficient diet for 6 weeks following which laparotomy was performed and peritoneal wounds of standard size were constructed,2. The diet resulted in a progressive weight loss and a fall in plasma protein. Tissue protein, expressed as percentage protein in dried voluntary muscle, did not fall significantly.3. Following laparotomy the rats were killed in groups on successive days and the peritoneal wounds were removed for measurement of area and for histological examination.4. There was no apparent difference between control and protein-deficient animals in the rate or extent of peritoneal wound contraction although there was histological evidence of delay of collagen formation in the protein-deficient animals. This supports the theory that collagen formation is not a function of wound contraction.

World Food Needs and "New Proteins"

This article is mostly not knowledge. Rather, it pulls together some chunks of knowledge that should be well known by this time but unfortunately are not-perhaps because the best reports have been published outside the main stream of the economic literature.' New commonly refers to any or all of the following: fish flour concentrate; the various processed plant protein foodstuffs (processed soybeans, peanuts, cottonseed meal, and other oil seeds); algae; yeast; petroleum; leaf protein; or any combination of these with each other or with conventional protein like milk. Collectively these proteins are sometimes referred to as new foods or food substitutes. Both terms are very deceptive, however, and have misled many students of the food-population problem. In fact, the main purpose of these proteins is not simply to substitute for the people commonly eat but are in short supply now or in the future, but rather to prevent protein deficiencies. This has been an important confusion. The two pressing nutritional needs are (a) calories, and (b) protein. The proteins are not particularly efficient sources of calories. But production of calories from conventional sources (e.g., wheat, rice, corn) is more expansible than is the production of conventional proteins (e.g., animal meat), in the sense that marginal cost of the latter rises faster than marginal cost of the former. Furthermore, calorie deficiency is less frequent throughout the world than is protein deficiency, especially among children,2 and the effects of protein deficiency have long-lasting destructive effects on body and mind.3 The horrible effects common in children are shown in the painful-to-look-at medical photographs reproduced in many UN publications. And the incidence of severe protein deficiency (known as Kwashiorkor) is very high among children in many countries.4 This is why the sources of protein are important in themselves, and not as substitutes for wheat, rice, or corn. And not only does protein prevent Kwashiorkor, but even a few months of sufficient protein in the diet produces truly miraculous cures in many children suffering from Kwashiorkor.5 However, the extent to which the disease damage is reversible is an

Effects of protein deficiency on certain adaptive responses to exercise.

Effects of protein deficiency on certain adaptive responses to exercise.

Effect of Protein Deficiency on the Spleen and Antibody Formation in Rats

As protein malnutrition frequently has been associated with lowered resistance and poor immune response, a study was undertaken to determine which aspects of the primary immune response may be impaired in protein deficiency and to describe such effects in terms of tissue components related to synthesis of plasma proteins. Protein-deficient and normal adult male rats were immunized with sheep erythrocytes and killed 6 days later. Spleens of protein-deficient rats were smaller and contained fewer cells, less nitrogen, less RNA, and more DNA per cell than those of controls. These changes were compared with those observed in liver as a result of protein depletion. In depleted animals, numbers of specific antibody-forming cells (AFC) and amounts of circulating antibody were about one-third of normal, while the amount of γ-globulin was two-thirds of normal. Since antibody production per AFC did not decrease in deficient animals, the depression of antibody titers in protein deficiency could be attributed largely to the reduction in numbers of AFC’s in the spleen.

Some Effects of Protein Deficiency on the Rat Thyroid1

The response of the thyroid of young growing rats exposed to protein deficiency was studied, and the effects of prolonged administration of propylthiouracil were measured. Control animals received a normal protein diet isocaloric with the average amount of food consumed by the deficient rats. The growth response was measured by gland weight, percentage of nuclei labeled with 3Hthymidine, and mitotic counts. Thyroid to serum radioiodide concentration ratios (T/S) were also determined as a functional index. A marked reduction in the growth response of the thyroid was observed in protein-deficient animals in comparison with the controls. This was associated with a striking 2- to 3-fold increase in the iodide concentrating ability of the thyroids in the deficient group as measured by the T/S ratio. No consistent changes were found in the distribution of labeled iodine or in the ratios of the iodinated amino acids among the thyroid cell particles and the soluble component. (Endocrinology 77: 87, 1965)

The Effect of Protein Deficiency on the Susceptibility of Human Amnion Cell (JTC‐3 Cell) to Viruses in Tissue Culture

The Effect of Protein Deficiency on the Susceptibility of Human Amnion Cell (JTC‐3 Cell) to Viruses in Tissue Culture

Effect of Protein Deficiency during Gestation and Lactation on Body Weight and Composition of Offspring

The effects of feeding a 7% wheat protein diet either during gestation or lactation, or both, on body weight and composition of offspring of rats at birth and weaning and the lactation performance of dams were studied. The difference between litter size, birth weight and body composition of the progeny of rats receiving the 18% mixed protein and the 7% wheat protein diet was negligible. The 7% wheat protein diet fed during gestation and lactation severely affected the quantity of milk produced but not the concentration of protein in the milk. Pups born to and suckled by mothers receiving the 7% wheat protein diet suffered 100% mortality. Pups born to rats receiving the 18% mixed protein diet but suckled by mothers receiving the 7% wheat protein diet showed very high mortality and the lowest weaning weight. Among those born to mothers receiving the 7% wheat protein diet but suckled by rats receiving the 18% mixed protein diet, the mortality was less and the weaning weight higher than in those of the above group. The highest weaning weight was shown in rats born to and suckled by mothers receiving the 18% mixed protein diet. The body fat, protein and ash content at the time of weaning in those rats stressed by protein deficiency during the prenatal or preweaning period was lower than those of the control rats.

Effect of protein deficiency and subsequent refeeding on body composition of adult rats.

Effect of protein deficiency and subsequent refeeding on body composition of adult rats.

The effect of protein deficiency on maze performance of domestic Norway rats.

The effect of protein deficiency on maze performance of domestic Norway rats.

The effect of thiamine deficiency on the resistance of rats to infection with spirochetes of relapsing fever.

The effect of protein deficiency on the resistance of rats to infection with relapsing fever has been reported in a previous publication from this laboratory.' It was demonstrated that protein deficiency results in a more severe degree of infection, a longer duration of attacks and a high fatality rate. This diminished resistance was found to be due only to a minor degree to the concomitant caloric deficiency but to a greater extent to the protein deficiency per se. In order to elucidate further the role played by calories in specific nutritional deficiencies, thiamine deficiency was chosen. This paper presents results obtained by the infection with relapsing fever spirochetes of normal rats and of rats with various degrees of thiamine deficiency.

The effect of protein deficiency on the resistance of rats to infection with spirochetes of relapsing fever.

The effect of protein deficiency on the resistance of rats to infection with relapsing fever has been reported in a previous publication from this laboratory.' It was demonstrated that protein deficiency results in a more severe degree of infection, a longer duration of attacks and a high fatality rate. This diminished resistance was found to be due only to a minor degree to the concomitant caloric deficiency but to a greater extent to the protein deficiency per se. In order to elucidate further the role played by calories in specific nutritional deficiencies, thiamine deficiency was chosen. This paper presents results obtained by the infection with relapsing fever spirochetes of normal rats and of rats with various degrees of thiamine deficiency.