Effects of growth hormone and insulin-like growth factor-1 on protein metabolism, gut morphology, and cell-mediated immunity in burned rats.

The effects of recombinant human growth hormone (GH) and insulin-like growth factor-1 (IGF-1) were investigated in burned rats. Sprague-Dawley rats were fed exclusively by total parenteral nutrition and were subjected to 20% third-degree scald burns. The rats were then divided into the following three groups: (1) the GH group received GH at a dose of 1 IU.kg-1.d-1 for 2d (n = 10); (2) the IGF group received IGF-1 at a dose of 4 mg.kg-1.d-1 for 2d (n = 19); and (3) the control group received saline (n = 17). Cumulative nitrogen balance increased significantly in the GH (P < 0.01) and IGF (P < 0.01) groups as compared with the control group. There were no differences in nitrogen balance between the GH and IGF groups. Blood glucose was decreased in the IGF group (P < 0.01) and increased in the GH group (P < 0.05) as compared with the control group. The intestinal villus height and wall thickness of the GH and IGF groups were significantly greater than those of the control group. Delayed-type hypersensitivity was enhanced in both the GH and the IGF groups as compared with the control group (both P < 0.01). Furthermore, the increase in the IGF group was significantly greater than that in the GH group (P < 0.05). It was concluded that both GH and IGF-1 improve protein metabolism and immune responsiveness, as well as promote proliferation of the intestinal mucosa.

The effect of increasing levels of fish oil-containing structured triglycerides on protein metabolism in parenterally fed rats stressed by burn plus endotoxin.

This report investigates the effect of various levels of medium-chain/fish oil structured triglycerides on protein and energy metabolism in hypermetabolic rats. Male Sprague-Dawley rats (192 to 226 g) were continuously infused with isovolemic diets that provided 200 kcal/kg per day and 2 g of amino acid nitrogen per kilogram per day. The percentage of nonnitrogen calories as structured triglyceride was varied: no fat, 5%, 15%, or 30%. A 30% long-chain triglyceride diet was also provided as a control to compare the protein-sparing abilities of these two types of fat. Nitrogen excretion, plasma albumin, plasma triglycerides, and whole-body and liver and muscle protein kinetics were determined after 3 days of feeding. Whole-body protein breakdown, flux, and oxidation were similar in all groups. The 15% structured triglyceride diet maximized whole-body protein synthesis (p < .05). Liver fractional synthetic rate was significantly greater in animals receiving 5% of nonprotein calories as structured triglyceride (p < .05). Muscle fractional synthetic rate was unchanged. Plasma triglycerides were markedly elevated in the 30% structured triglyceride-fed rats. The 30% structured triglyceride diet maintained plasma albumin levels better than those diets containing no fat, 5% medium-chain triglyceride/fish oil structured triglyceride, or 30% long-chain triglycerides. Nitrogen excretion was lower in animals receiving 30% of nonnitrogen calories as a structured triglyceride than in those receiving 30% as long-chain triglycerides, but this difference did not reach statistical significance (p = .1). These data suggest that protein metabolism is optimized when structured triglyceride is provided at relatively low dietary fat intakes.

[The normal digestion of protein-containing food products by gastric juice and in pathology of the gastrointestinal tract]. / Perevarivanie beloksoderzhashchikh pishchevykh produktov zheludochnym sokom v norme i pri patologii zheludochno-kishechnogo trakta.

The authors describe a method designed by them for assessing gastric juice proteolysis relative to different protein-containing foods, commonly used in nutrition (beef, pork, mutton, etc). Investigations involved the use of gastric juice from healthy persons and patients with chronic gastritis associated with low secretory gastric function and ulcer disease. The proteolytic activity of gastric juice turned out to be different both in healthy persons and in patients with ulcer disease. In patients suffering from chronic gastritis associated with low secretory gastric function, proteolysis of protein-containing foods was reduced to a different degree in respect to a concrete food. Out of all foods investigated, egg yolk, beef liver and mintai were assimilated better whereas egg white and mutton to a worse degree. Addition of hydrochloric or citric acid raised the proteolytic activity of gastric juice.

[The experimental effect of growth stimulants on protein assimilation]. / Vliianie stimuliatorov rosta na assimiliatsiiu belka v éksperimente.

In experiments on rats it was established that the compound CAM-300 in a dose of 2 mg/kg did not induce body mass growth, protein biological value increase or pepsinogen concentration change in the gastric mucosa. Fenobolin stimulation of growth in the experimental animals was attended by a three-fold rise in pepsinogen concentration in the gastric mucosa, the pure utilization of protein being unchanged. The action of the compound 6-(6,10-dioxyundecyl)-beta-resorcin acid gamma-lacton (International Minerals Corporation) did not change biological value and the pure utilization of protein, pepsinogen concentration in the gastric mucosa was slightly lowered. Evaluation of the pure utilization of protein is the principle test in the estimation of the compound anabolic effect.

[The nutritional status characteristics and the protein metabolic indices of children with acute leukemia]. / Osobennosti pishchevogo statusa i nekotorye pokazateli obmena belka u detei, bol'nykh ostrym leikozom.

The nutritive status features and the main parameters of nitrogen metabolism were investigated in 212 children with acute leukemia at varying stages of the disease. A study was made of the patients' body mass, nitrogen balance, excretion of nitrogenous compounds with urine and feces, total protein and albumin content in the blood, as well as blood content of urea, creatinine, amino nitrogen and uric acid. The results of the study have shown a negative influence of both leukemia and its therapy on the nutritive status of the patients, that was manifested in protein-energy deficiency and in protein assimilation disorders. A relationship has been revealed between infectious complications, preventing the successful treatment, and the nutritive status of the patients. Clarification of these pathogenetic mechanisms of the negative action of the disease itself and antileukemic therapy will help in the realization of the purposeful correction.

[The effect of a peripheral beta-adrenergic blockade on protein absorption in the small intestine in the early postoperative period]. / Vliianie perifericheskoi beta-adrenoblokady na vsasyvanie belka v tonkoi kishke v rannem posleoperatsionnom periode.

It was demonstrated in experiments on dogs that enteral absorption of protein occurs in phases. An operative trauma reduces the rate and duration of absorption, disorganizes the phase structure of the process, and reduces the supply of protein to the organism. Obzidan blockade of the beta-adrenergic structures restores the rate, duration, and time organization of absorption and thus increases the entry of protein into the organism.

The digestive and metabolic utilization of the dietary protein: effect of clenbuterol and protein level.

The influence of a beta-agonist, clenbuterol, added to the diet at 0, 30 and 50 mg/Kg was studied on the digestive and metabolic use of the dietary protein in Wistar rats of two different weights (70 and 200 g). The rats had been fed diets containing different protein levels (4, 10 and 15%). Treatment with clenbuterol did not have any effects on the absorption of the dietary protein in any of the studies released. The beta-agonist did not alter fecal nitrogen excretion nor did it change the digestion coefficient of the protein at the doses used. Clenbuterol significantly increased (P less than 0.01) urinary nitrogen excretion in younger animals fed diets containing low levels of protein (4%). On the other hand, in animals of greater age/weight that had been fed diets with a sufficient protein content (15%), the beta-agonist significantly reduced urinary nitrogen excretion (P less than 0.001). From the results of this study, it can be concluded that in order that clenbuterol can significantly increase nitrogen balance and protein retention, the animals must be given a sufficient exogenous protein intake and they must not be at a stage of maximum growth potential.

Forestomach and whole tract digestion in lactating dairy cows fed canola meal treated with variable levels of acetic acid.

Five Holstein cows in midlactation were fed four isonitrogenous (mean 2.76% N) mixed diets containing untreated canola meal or replaced with canola meal treated with 0, 33, 67, or 100% of acetic acid in a 12-wk 4 x 4 Latin square experiment. Diets were 50% barely-based concentrate, 12% canola meal, 30% whole crop oat silage, and 8% alfalfa silage (DM basis). Fore-stomach and whole tract apparent digestibilities of DM, OM, and its components, including fiber and CP, did not differ as proportions of treated canola meal increased. Rumen pool sizes of OM, NDF, and bacterial OM, as well as total NAN and bacterial N, were not influenced by treatment, although bacterial N pool size tended to decline as treated canola meal replaced untreated. This result was consistent with a trend for reduced flow of bacterial N at the duodenum. Duodenal flow of AA protein, and its profile, was not influenced by treatment. Results suggest that low level replacement of untreated canola meal with canola meal treated with acetic acid stimulated microbial growth by providing more sustained delivery of slowly degraded true protein. However, at higher substitution, the rumen microbial pool was reduced progressively, perhaps because of a shortage of readily fermentable N. This hypothesis, although not consistent with all data, seems to be the most plausible explanation for all observations, although it is clear that differences in both digestion and duodenal flow, particularly for protein, attributable to replacement of untreated canola meal by that treated with acetic acid were moderate.

Guanidinated protein test meals with higher concentration of soybean trypsin inhibitors increase ileal recoveries of endogenous amino acids in pigs.

The amino acid concentrations of cornstarch-based guanidinated unprocessed (UGM) and autoclaved (AGM) Nutrisoy (defatted soy flour) protein test meals were compared with the respective unguanidinated Nutrisoy diets. Endogenous ileal recoveries and true digestibilities of amino acids were determined in six growing pigs, fitted with a simple T-cannula at the distal ileum, fed the guanidinated protein test meals. The UGM and AGM contained 13.4 (high) and 3.0 (low) g/kg dry matter of soybean trypsin inhibitors (SBTI), respectively. The experiment was a two-period cross-over design with each period lasting 15 d. On d 14 of each period, the pigs were fed the guanidinated test meals followed by 24 h continuous collection of digesta. Concentrations of crude protein and most of the amino acids in the test meals were higher than in the respective diets. Apparent ileal amino acid digestibilities of the test meals did not differ (P > 0.05) from reported values for the respective diets and were higher (P < 0.05) by 22.7 (cysteine) to 61.3 (tyrosine) percentage units for AGM compared with UGM. The ileal recoveries of endogenous amino acids in AGM-fed pigs were lower (P < 0.05) than UGM-fed pigs. Values ranged from -0.10 (arginine) to 0.64 (aspartate + asparagine) and from 0.84 (histidine) to 2.61 (tyrosine) g/kg dry matter intake for AGM- and UGM-fed pigs, respectively. True ileal amino acid digestibilities for AGM were higher (P < 0.05) than UGM with differences ranging from 12.7 (tyrosine) to 38.3 (leucine) percentage units. In conclusion, ileal recoveries of endogenous amino acids were increased in pigs fed guanidinated protein test meals with the higher concentration of SBTI.

Effects of a beta-adrenergic agonist (clenbuterol) on performance, carcase composition, hepatic microsomal mixed function oxidase and antibody production in female broilers treated with or without corticosterone.

1. Beta-adrenergic agonist (Clenbuterol, 0.33 mg/kg) and corticosterone (10 mg/kg) were incorporated into a diet based on maize and soybean meal. Their effects on performance, carcase composition, hepatic microsomal mixed function oxidase and antibody production were investigated in female broilers. 2. Dietary corticosterone reduced the titre to sheep red blood cells, while it was unchanged by clenbuterol. 3. Clenbuterol exerted a promoting effect on gain-to-food ratio, carcase protein and hepatic microsomal cytochrome P-450 content. 4. Addition of clenbuterol to the corticosterone-containing diet prevented the increase in abdominal fat weight and uric acid excretion induced by corticosterone, but did not affect total fat mass. 5. The results showed that clenbuterol reduced abdominal rather than carcase fat and prevented protein degradation in the body when chicks were treated with corticosterone. Clenbuterol also influenced the content of cytochrome P-450, but not the humoral immunity.