the 20 common in proteins: ornithine & citrulline. Urea secreted to bloodstream→ KIDNEYS→excreted in URINE. 3) URIC ACID. Birds & terrestrial reptiles (the. EXPERIMENTAL PARASITOLOGY , (19%) Protein Metabolism 5. Trichostrongylus colubriformis: Changes of Host Body Mass and Protein Synthesis. the net formation of protein is accelerated by insulin. The effects of insulin on protein metabolism take place inde- pendently of the transport of glucose or amino.
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In a review written about four years ago in the British Medical. Bulletin ( Neuberger, ), the change in our concept of protein metabolism brought about by the. Protein Metabolism. V fused organs with a-keto acids and ammonia and obtained the corresponding amino acids. Neber (4) treated mixtures of pyru- vie acid. PROTEIN METABOLISM. TRANSAMINATION OF AMINO ACIDS. Transaminases catalyze the transfer of -NH2 groups from the amino acids, onto alpha-.
Forgot Password? The two reacting molecules are the alpha amino group of one amino acid and the alpha carboxyl group of the other amino acids. New York. Terpenoid backbones. Protein biosynthesis. After translational initiation which is different in prokaryotes and eukaryotes , the ribosome enters the elongation period which follows a repetitive cycle.
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Trichostrongylus Changes of host body mass and protein synthesis in guinea pigs with light to heavy infections.
Experimental Parasitology 44, Guinea pigs with light to heavy infections of Trichostrongylus colubdformis were used to examine the relationships between the fall of food consumption and the changes of body mass and skeletal muscle and liver protein synthesis. The faster loss of body mass and the greater depression of the rate of muscle protein synthesis in relation to falling food consumption and the faster rate of liver protein synthesis in infected than in pair-fed animals indicated that anorexia was not solely responsible for the metabolic changes in intestinal nematode infection.
Factors that may exacerbate the effect of anorexia are briefly discussed. Trichostrongylus colubriformis; Parasitic nematode; Guinea pigs; Pathophysiology; Protein synthesis; Skeletal muscle; Liver; Anorexia; L-leucine incorporation; Body mass.
Previous experience indicated that anorexia was a reliable measure of the severity of the effects of infection. This observation was extended by examining the relationship of food consumption, changes in body mass and muscle, and liver protein synthesis to worm count. For instance, it was assumed that the intestinal loss of serum proteins that stimulates liver protein synthesis would exacerbate the effect of anorexia on muscle protein synthesis Symons et al.
The aim of the present experiment was to reexamine the importance of anorexia by comparing the effects of infection and pair feeding on changes of body mass and skeletal muscle and liver protein synthesis. Animals were weighed daily.
The animals were divided into three groups: The infection of guinea pigs with similar numbers of larvae would result in considerable variation in the numbers of adult parasites in individual hosts, so that consequently their pathophysiological responses would range from slight to severe. The severity of infection was assessed by changes of body mass, food consumption, and gross intestinal morphology.
Experience had shown that these were more reliable guides than was worm count. Animals in the infected and pair-fed groups were paired according to mean food consumption calculated from a 3- or 4-day preinfection phase. Pair feeding began the day after infection, i. Allowance for the hr delay between infected and pair-fed groups was made in subsequent calculations.
The daily consumption of the ad lib. Injections were made between and hr and the animals were fed immediately afterwards and killed 24 hr later. The isotope was administered to the pair-fed animals the following day. Care was taken to standardize the injection of the isotope to avoid the low specific activity that occasionally occurred in both skeletal muscle and liver proteins. Because of good agreement in earlier experiments between the results of measurements of incorporation by an in viva technique and by an isolation of ribosomes from muscle and liver, only the former method was used in the present study.
The methods used for the removal of these tissues and for subsequent assays were essentially those previously described Symons and Jones Samples of 1 g of the liver and the pooled rectus femori muscles were homogenized in water and made to 20 ml. Contents of the gastrointestinal tract. The contents were estimated from the full and empty gastrointestinal tract and expressed as a percentage of body mass.
Calculations and statistical analyses. The relationship between changes of body mass and food consumption was examined from two points of view. In the first, the change of body mass was estimated as the difference between masses at the start of the infection or pair feeding and at the end of the experiment. Adjustment was made to final body masses for the difference in gastrointestinal contents between infected and pair-fed animals.
Change in food consumption was estimated as the difference between the mean of 3 days prior to infection or pair feeding and the mean of the final 2 days.
Second, the loss of body mass was calculated as the difference between Trichostrongylus colubriformis: No adjustments for gastrointestinal contents were made in this instance because it was assumed there was no change of contents in the short time interval between maximum and final body mass.
Reduction of food consumption was estimated as the difference between the mean consumption 3 days prior to maximum body mass and the mean consumption of the final day of the experiment. Standard deviations of the differences between intercepts for the regression of incorporation at zero reduction of consumption were calculated, and differences between intercepts were examined by t tests.
Regression analyses were also made of worm counts on changes of food consumption and body mass between the beginning and the end of the experiment and the incorporation by muscle and liver. Analyses of variance or t tests were made where appropriate.
The body masses of the guinea pigs infected with Trichostrongylus colubriformis and pair-fed guinea pigs fell during the early stage of the infection, recovered to reach a maximum greater than the initial mass, and decreased rapidly with the onset of anorexia.
When expressed as a percentage of body mass there was no difference between the gastrointestinal contents of uninfected animals whether fed ad lib. The contents of eight infected guinea pigs were significantly greater than that of eleven uninfected animals When allowance was made for this difference in gastrointestinal contents the data suggested that the change in body mass between the beginning and the end of the experiment in relation to the change in food consumption was greater in the infected than in the pair-fed animals, but the difference was not significant Fig.
Relationship of changes of body mass and of food consumption between the beginning and the end of the experiment in guinea pigs infected with Trichostwngylus colubriformis and in uninfected pair-fed animals.
Difference between slopes: Relationship of the loss of body mass from the maximum and the reduction of food consumption over the final days in guinea pigs infected with Trichostrongylus colubriformis and in uninfected pair-fed animals. The data suggested that there was a faster rate of loss from maximum body mass y with large decreases of food consumption x in the infected than in the pair-fed guinea pigs.
Hence, since a common relationship in loss of mass for small decreases in consumption was probable and consistent with the data, the following model was adopted to describe these relationships: Thus the relationships for the two groups were constrained to have common parameters bo and b, , the difference between them being the quadratic term bzx2 which represents both nonlinearity of the relationship in the infected animals and differences between the two.
The relationships were fitted simultaneously to obtain pooled estimates of the common parameters.
A t test on the estimate of b2 was used to assess the significance of nonlinearity in the relationship for the infected animals as well as differences between them and the pair fed. The rate of loss of body mass increased with the fall in food consumption of the infected group but did not change significantly with consumption by the pair-fed animals Fig. Protein syrdesis. Disparity between the numbers of guinea pigs from which the data in Fig. The relationship between the incorporation of L- [W] leucine into skeletal muscle and food consumption is shown in Fig.
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