Effect Of High Protein Diet Research Articles

Renal and Systemic Effects of Short-term High Protein Feeding in Normal Rats

Various studies have shown that a high protein (HP) diet, compared to a low protein (LP) diet, leads to hypercalciuria and alterations in renal and systemic hemodynamics. The authors compared the effects of HP diet to those of normal protein diet (NP) to determine the possible mechanisms by which changes in systemic hemodynamics and hypercalciuria occurred. The studies were conducted in awake rats; the effects of dietary sodium content on the changes induced by HP also were evaluated. The relationship of prostaglandins (PG), renin (PRA), and aldosterone (PA) to changes in blood pressure (BP) was assessed. Two weeks after HP and normal sodium feeding (40%), glomerular filtration rate (GFR) and urine flow (V) were not different from the same values in a group on an NP diet (23%). When HP was fed with low sodium, there was a rise in V as a consequence of greater fluid intake. Although plasma calcium remained constant, the hypercalciuria correlated with high protein and sodium content. Alterations in 1,25(OH)2 vitamin D3 or PTH (cyclic AMP excretion) function did not explain the hypercalciuria induced by HP. This suggests that HP leads to inhibition of tubular calcium reabsorption by mechanism(s) yet to be elucidated. Although HP did not alter GFR, it led to an increase in BP, a fall in renal vascular resistance, and an increase in RPF, regardless of sodium intake. PRA and urine PGE2 excretion were significantly higher in the rats on HP diet, whereas PA remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Respiratory Insufficiency in Acid Maltase Deficiency: The Effect of High Protein Diet

A 27-yr-old woman with the myopathic form of acid maltase deficiency (AMD) developed severe respiratory insufficiency after a crash diet resulting in a 6-kg weight loss. While being maintained on home ventilation, an hypercaloric high-protein, low-carbohydrate diet (1800-2000 cal; 28% carbohydrates, 55% fat, 17% protein with 1.7 g protein/kg body weight) was instituted. This ameliorated her condition up to a level where useful life was possible and ventilation could be diminished.

Effects of high protein diet and sodium bicarbonate supplementation on calcium metabolism in rats.

This study was conducted to determine the effect of a high protein diet on calcium metabolism in rat. Wistar strain male rats (50 days old) were divided into 5 groups (day 0): control diet (18% casein); high protein diet (18% casein +20% lactalbumin); high protein and 0.1% sodium bicarbonate diet; high protein and 0.2% sodium bicarbonate diet; and high protein and 0.4% sodium bicarbonate diet. On days 0, 1, 3, 5, 7, 9, urine samples were collected and, at the same time, feces were collected from half of the animals in each group. Urinary titratable acidity (TA-HCO3-), ammonium ion (NH4+), and net acid excretion (NAE) were measured as an index of acid-base balance in rat body. Urinary volume was rapidly increased and the increase of urinary volume continued throughout the study in rats fed the high protein diet. Urinary excretions of calcium and phosphorus were increased after day 3 and day 1, respectively, in rats fed the high protein diet. The high protein diet depressed calcium absorption and elevated phosphorus absorption from the digestive tract in rats fed the high protein diet. The high protein diet decreased TA-HCO3-, which was closely correlated with the decrease of NAE. Sodium bicarbonate supplementation to the high protein diet had little effect on urinary calcium excretion and NAE. This study suggested that there was no relationship between metabolic acidosis and hypercalciuria in rats fed the high protein diet.

Alleviating Effect of High Protein Diet on the Toxic Effect of Organophospho~C ompounds on the Growth of Rats

Elevation of protein in the diet from 19 to 59 per cent ,and keptisocaloric significantly improved the growth over a period of 20 days of male albino rats exposed to the toxic stress of DFP, EPN and Malathion.

Flow cytometric analysis of the effects of high protein diet on isolated rat liver mitochondria.

We have investigated changes that occur in mitochondria obtained from the livers of rats that had been maintained on a high protein diet (80% casein instead of 20%) for 6 months. Liver homogenates were separated by centrifugation into a mitochondrial fraction, a nuclear fraction and the supernatant fluid of the nuclear fraction (nuclear wash). Rhodamine-123 was used to selectively stain mitochondria depending upon their membrane potential. The stained organelles were processed through a flow cytometer where the fluorescent stains were excited by the 488 nm wavelength of a laser and the resultant fluorescence signals analysed. After 6 months on a high protein diet, mitochondria displayed an increase in the fluorescence associated with rhodamine-123 uptake in both mitochondrial and nuclear wash fractions, while mitochondrial fluorescence in the nuclear fraction showed a heterogeneous distribution. This was interpreted as an increase in membrane potential in most of the liver mitochondria under these nutritional conditions, with a certain degree of heterogeneity. These functional changes may be correlated with morphological alterations previously reported and show the usefulness of flow cytometry for biochemical analysis of isolated mitochondria.

Effects of a high protein diet on the evolution of diabetes in streptozotocin-induced and spontaneously diabetic "BB" Wistar rats.

Recently, we demonstrated a reduction in the diabetogenic action of streptozotocin (STZ) in rats previously adapted to a high protein (HP) diet. These data suggested that amelioration of diabetes resulted from the combination of two effects of the HP diet: initial protection against the diabetogenic action of the drug at the time of exposure and subsequent improvement of the induced diabetic condition. The present study evaluated the effects of a HP diet on the evolution of the metabolic condition in rats with STZ-induced or spontaneous diabetes (BB Wistar rats). Two days after STZ injection, the animals were given isocaloric HP (70% protein, 8% fat) or control (66% carbohydrate, 16% protein, 8% fat) diets for 15 days. After 13 days, the STZ-treated rats fed HP diet showed an impressive decrease in severity of diabetes, as judged by rate of body weight change, plasma glucose, urine volume and glycosuria, serum and pancreatic insulin. The BB Wistar rats, already diabetic for 5 weeks before being transferred to the HP or control diet, were treated with daily injections of insulin. After 31 days on the HP diet, the BB rats showed reduced insulin requirement, reduced blood and urinary glucose levels, but no difference in body weight gain or pancreatic insulin content. The data show that short-term use of HP diets can greatly improve the diabetic condition in STZ-treated animals, but that the beneficial effects of the diet are much less marked in rats with chronic spontaneous diabetes. These data suggest that the ameliorating effect of HP diet is fully manifested only when the diabetic rats have a sufficient number of residual functioning B-cells.

EFFECT OF DIETARY HIGH PROTEIN ON THE PREVENTION OF ATHEROGENESIS IN RATS

Stroke-prone spontaneously hypertensive rats (SHRSP) were fed on a high-fatcholesterol diet containing low or high protein and effects of dietary protein on the development of atherogenesis were investigated. Intake of protein-rich diet of both fish and soybean origin had marked preventive effects on atherogenesis in cerebral and mesenteric arteries in SHRSP even on the atherogenic diet. Further, preventive effect of high protein diet was more marked in the group on a fish-protein-rich diet in comparison with that on soybean-proteinrich diet.

Effects of High Protein Diet on Insulin and Glucagon Secretion in Normal Rats

The effect of a high protein diet on blood glucose, insulin, and glucagon secretion was studied in the peripheral blood and isolated perfused pancreas of normal rats. A balanced diet (protein 27%, carbohydrate 61%, fat 12%) and a high protein diet (protein 55%, carbohydrate 30%, fat 15%) were given ad libitum to normal rats for 2 weeks. No significant difference in calorie intake or body weight changes were observed between the two groups. Fasting blood glucose and plasma insulin concentrations in rats fed the high protein diet were significantly higher than those in rats fed the balanced diet. The fasting plasma glucagon concentration, however, was the same in both groups. In the isolated perfused pancreas, the arginine-induced insulin secretion in rats fed the high protein diet was significantly higher than that in rats fed the balanced diet, whereas the arginine-induced glucagon secretion was not different in either group. The possible mechanism by which a high protein diet causes hypersecretion of insulin in vivo and in vitro are discussed.high protein diet insulin glucagon isolated perfused rat pancreas

Effects of dietary protein on urinary calcium in normal subjects and in patients with nephrolithiasis

The effect of high-protein diets on the excretion of calcium in urine was evaluated in four normal persons and in four patients with nephrolithiasis. All subjects were housed in a metabolic unit and given constant metabolic diets each day containing 0.5 g protein/kg and 300–600 mg calcium, 1000 mg phosphorus, and 69 mEq sodium. During the experimental phase, each person received an additional 1.5 g protein/kg/day consisting of purified casein, gluten, lactalbumin, and gelatin. There was a consistent increase in urinary calcium with the high-protein diet, averaging 88% above control in the normals and 82% in the patients. In addition, the normal subjects showed significant ( p < 0.05) increases in urinary phosphorus (mean increases, 219 ± 53 mg/d, mean ± SE), nitrogen (8.8 ± 0.9 g/d), titratable acid (19 ± 5 mEq/d), and ammonium (22 ± 3 mEq/d), whereas the patients showed increases in urinary magnesium (18 ± 2 mg/d), nitrogen (12 ± 1.0 g/d), and ammonium (34 ± 2 mEq/d), and in creatinine clearance (14 ± 3 ml/min). In both groups, there was a small increase in the filtered, excreted, and reabsorbed calcium and a small decrease in the percentage reabsorption of calcium. Serum chemical values did not change from values with the low-protein diet. In two of the patients who were known to be hyperabsorbing calcium, sodium cellulose phosphate (chelator of intestinal calcium) reversed the increase in urinary calcium produced by the high-protein diet. In the remaining patients, neither sodium cellulose phosphate nor a low-calcium diet could counteract the increase in excretion of calcium with the diet. It is concluded that a high-protein diet can increase urinary calcium by altering renal function and/or increasing intestinal absorption of calcium and that dietary protein must be considered in the evaluation and treatment of patients with hypercalciuria and nephrolithiasis.

Effect of high protein diet on cerebral blood flow and cerebrovascular reactivity in rats [proceedings

As we previously reported and reconfirmed, SHRSP fed on the normal diet developed stroke, in average, at the age of 9 months in males. However, in the present study, SHRSP fed on the high protein (soybean protein in this study) diet maintained the normal range in both rCBF and chemical cerebrovascular reactivity in spite of the development of severe hypertension at the age of 8 month. These experimental results substantiated prophylactic effect of high protein diet on stroke from the view point of mechanism of stroke mentioned above in the introduction

Prophylactic Trials for Stroke in Stroke-prone SHR

This study confirmed again that high protein diet feeding decreased the incidence of stroke, and high fish protein diet did attenuate severe hypertension but high soybean protein diet did not affect the hypertension. Dietary amino acid analyses indicated that increases in total amino acids, essential amino acids and nonpolar amino acids but not acid or basic amino acids were significantly related to the reduction of stroke incidence. Among essential amino acids, lysine, threonine, isoleucine, and leucine contents were inversely related to stroke incidence, and methionine content was significantly related to the dietary antihypertensive effect of high protein diets. The prophylactic effect of high protein diets may be ascribed to some amino acid constituent.

Effect of high-protein diet on rat heart mitochondria after exhaustive exercise.

Effect of high-protein diet on rat heart mitochondria after exhaustive exercise.

Age and Breed Difference in the Effect of Dietary Protein on Carcass Fat Deposition of the Chicken

It has been reported that starting chicks and growing meat-type chicks can easily become fatty or lean by simply changing dietary levels of protein, but, in striking contrast, dietary protein levels have little effect on abdominal fat content of laying hens. In this paper, is reported the effect of dietary levels of energy and protein on the body fat deposition of growing chicks of both sexes of two strains at various ages.Both males and females of White Leghorn or meat-type cross-breds were sacrificed at 4, 6, 8, 12, 16 and 20 weeks of age for abdominal fat determination. Abdominal fat was determined because it has highly significant correlation with body fat deposition. Therefore, the latter can be estimated from the former. Except those sacrificed at 4 and 6 weeks of age, 24 males and 24 females were moved from the farm of National Institute of Animal Industry into the chick room kept at constant temperature of 20°C., and divided into 16 groups of 3 chicks each. One of the 4 experimental diets was fed to duplicated lots of males and females for 25 days before the determination of abdominal fat. Two-week-old chicks were reared in an electrically heated battery brooder for 2 weeks in the chick room on the experimental diets and sacrificed at 4 and 6 weeks of age as mentioned above.The combination of 2 levels of crude protein and 2 levels of metabolizable energy (kcal/g air-dry diet) prepared 4 experimental diets. Their contents were determined to be 14.8%-3.00kcal/g, 14.9%-2.52kcal/g, 20.4%-2.97kcal/g and 20.2%-2.47kcal/g, respectively.Effect of dietary energy and protein levels on abdominal fat deposition was analyzed statistically at various ages, and following results are obtained:1) Higher dietary energy level resulted in more deposition of abdominal fat in all stages of growth, except females at 20 weeks of age. Females at 20 weeks of age deposited large amount of abdominal fat even on low energy-high protein diet, presumably related with the sexual maturity of females.2) Higher level of dietary protein depressed fat deposition of White Leghorn chicks of both sexes at 8 weeks or younger and of meat-type chicks of both sexes at 12 weeks or younger. Little difference in abdominal fat deposition was observed between the chicks older than mentioned above, fed either high or low protein diets. It was also observed that the effect of high protein diet on fat deposition disappeared earlier in females than in males. These findings suggest that the depressing effect of dietary protein on fat deposition is related with sex hormones.3) In young chicks, on which the depressing effect of dietary protein on fat deposition was seen, the increase in dietary protein level by 5.5% approximately corresponded to the decrease in dietary metabolizable energy by 0.5kcal/g, in other words, one g of dietary protein apparently corresponded to -9.09 (=0.5/0.055) kcal of metabolizable energy, which closely resembles to -9.44kcal reported previously.4) Body fat deposition is related to actual intake of energy and protein rather than to their dietary content. However, it was revealed that change in feed intake under the experimental condition was so small that it was negligible in the discussion on fat deposition, except the change in feed intake of young White Leghorn chicks at 6 weeks of age. Dietary protein level of 14.5% seemed to be too low for young chicks and feed intake of the low protein diet was less than that of the corresponding high protein diet. This difference in feed intake had influence on fat deposition.

Effects of High Protein Diets with Normal and Low Energy Intake on Wound Healing, Hair Growth, Hair and Serum Zinc, and Serum Alkaline Phosphatase in Dairy Heifers

Effects of level of protein and energy intake on several measures were studied in 24 female Holstein calves. The four dietary treatments which provided varying amounts of protein and energy in relation to National Research Council (NRC) requirements were: a) control (100% protein, 100% energy); b) medium high protein (150% protein, 100% energy); c) high protein (200% protein, 100% energy); and d) high protein, restricted intake (same diet as high protein fed at a level to provide 60% of energy needs). Healing was more rapid in animals fed the high protein diet at 100% of energy requirement. Those given the high protein, restricted intake treatment healed at a rate comparable to that of controls, thus indicating that total protein intake had more influence on rate of healing than level of energy intake. Average daily gains were increased, and feed efficiency and hair growth rate slightly increased in those given the high protein treatments. Hair and serum zinc content, serum alkaline phosphatase, packed cell volume (PCV), and hemoglobin values were not materially affected by higher than normal dietary protein intakes. Restricting intake of the high protein feed reduced weight gains, feed efficiency, hair growth, and serum alkaline phosphatase, but did not affect hair and serum zinc, PCV, and hemoglobin values.

Further analysis of various renal functions in the Korean. II. Effect of high protein diet on water metabolism and renal functions.

Further analysis of various renal functions in the Korean. II. Effect of high protein diet on water metabolism and renal functions.

Effects of High Protein Diet on Mouse Kidney

Effects of High Protein Diet on Mouse Kidney

The Effect of High-Protein Diets on Renal Hypertrophy in Rats after Whole-Body Irradiation

Abstract : The relationship between high protein intake and increase in kidney weight was investigated in rats exposed to a single dose of 375 rad X-irradiation. Attempts were made to characterize the degree of renal hypertrophy and hyperplasia nvolved by employing irradiation as an inhibitor of cellular proliferation. Rats were fed a high protein diet and exposed to irradiation at various points of the feeding regime. The high protein diet significantly increased kidney weight in all cases but the increase was not influenced by the X-ray dose employed, or time of administration. However, histological studies of the kidneys showed that irradiation reduced the incidences of abnormal tubular hyperplasia. The renal lesions also appeared much earlier than previously reported by other investigators. Rats fed high protein diets appeared to recover body weight loss from the irradiation at a faster rate than those fed a basal diet. A possible mechanism is briefly discussed. (Author)

Chronic renal insufficiency. I. Appraisal of the patient. II. Treatment.

Excerpt Progress in the treatment of renal insufficiency has been spectacular in the past few years. We have seen a changing point of view with respect to the healing or alterability of renal lesio...

Effect of high-protein diet and urea administration on the blood pressure of normal dogs and of dogs with experimental renal hypertension

The administration of a high-protein diet (lean raw meat) to normal and hypertensive dogs for a long or short period of time failed to produce a consistent rise or fall in systolic or diastolic blood pressure. The administration of urea, intravenously or by stomach tube, to normal and hypertensive dogs likewise failed to produce any significant change in blood pressure. In one hypertensive dog there was a slight to moderate rise of systolic and diastolic blood pressure after each of the four experimental procedures.

EFFECT OF HIGH PROTEIN DIETS ON SIZE AND ACTIVITY OF THE ADRENAL CORTEX IN THE ALBINO RAT1

AREVIEW of the literature of adrenal hypertrophy (Tepperman, Engel and Long, 1943) revealed that many of the circumstances in which - such hypertrophy occurs are characterizied by either a relative or absolute increase in the rate of protein catabolism. This fact recurred so insistently that the reviewers have classified the ‘causes’ of adrenal hypertrophy according to the characteristics of their nitrogen economy. On the basis of this suggestion, and in the light of the hypothetical chemical sites of action of the cortical steroids of the corticosterone type, experiments were devised to test the effect of high protein diets on adrenal size. This study was undertaken in an effort to determine whether or notevidence of increased adrenal cortical activity could be secured in animals which were forced to derive a large proportion of their carbohydrate from protein. In addition to morphologic evidence of increased cortical activity