Protein, amino acid contents and protein efficiency ratio of Egyptian buffalo meat under different biological conditions

The effect of age, sex, season and cut variations on the protein, amino acids contents and protein efficiency ratio (P.E.R.) of Egyptian Buffalo meat was studied in 128 samples. Statistical analysis for the data obtained showed significant difference at 0.01 level for protein in relation to cut (abdomen and thigh, respectively), male in relation to season and dry season in relation to sex. There is also significant difference at 0.05 level in case of green season in relation to sex. Protein shows a significant difference at 0.1 level due to sex variation. There is a difference in the amino acids content of young and old animals during dry season in both cuts. Young animals show higher values than old ones in most of the amino acids investigated. There is also an obvious difference in the amino acids during green season between male and female animals, and also between both cuts. P.E.R. of Egyptian Buffalo meat as 10% protein level ranges between 3.02 and 2.35 according to seasonal, cut and age variations.     

Longitudinal changes of brain amino acid content occurring before, during and after epileptic activity

In cats affected with cortical epileptogenic foci induced by penicillin application to and cobalt implantation into the pericruciate area, the brain amino acids contents were determined in the focus as well as in extrafocal areas. In different groups of animals, brain removal for biochemical determinations was performed at different times before, during and after epilepsy and the values compared to controls. The only amino acid to show a significant change before appearance of spikes in both types of epilepsy was taurine, which decreased. Cobalt epilepsy was accompanied by changes in a larger number of amino acids than penicillin epilepsy: in the former the brain content of taurine, GABA, aspartate, glutamate, serine, threonine, glycine and alanine was altered. The changes were proportional to the severity of epilepsy and more prominent in the focus area. After disappearance of spikes the levels of most amino acids returned to normal except for some amino acids, previously unaffected by penicillin epilepsy, which were decreased. It is proposed that the decrease in brain taurine, occurring before the appearance of penicillin and cobalt epilepsy, could increase the excitability of a certain neuronal population and thus, by potentiating the effects on neurons of penicillin and cobalt, contribute to the initiation of epilepsy.     

The importance of collagen in the biological value of meat

Rat experiments showed that increases in the levels of collagen from 6.1 to 15.5% of the total content of meat proteins enhanced the growth and weight indices of animals. The differences in the biological value of the above quantity of collagen for man and rats were attributable to different physiological requirements for the quality of protein. Therefore, the findings in man are in agreement with those in rats.     

Protein and amino acid metabolism in chronic renal failure

We investigated the inhibitory effect of clarithromycin, a 14-membered ring macrolide antibiotic, on tumor-induced angiogenesis in vivo using a mouse dorsal air sac model. The inhibitory effect of clarithromycin was dose-dependent, and 100 mg/kg of clarithromycin administered intraperitoneally twice a day reduced the area of dense capillary network to about 30% that of the control. However, in concentrations up to 50 microM clarithromycin had no effect on lung cancer cells and human vascular endothelial cell growth, endothelial cell migration, or lung cancer cell production of the angiogenesis-inducing factors interleukin-8 and vascular endothelial growth factor. Clarithromycin in concentrations greater than 10 microM inhibited endothelial cell tube formation on Matrigel in a dose-dependent manner. These data suggest clarithromycin is a potent inhibitor of tumor-induced angiogenesis that exerts its effect by inhibiting endothelial cell tube formation, and may be a possible candidate for therapeutic application.     

Amino acid composition and biological value of rice proteins]

The study concerns the effect of angiotensin II when infused into the systemic and portal blood flow upon the general and renal haemodynamics in normal dogs and in hypertensive animals, as well as the effect of the operation of porto-caval transposition upon the course of renovascular hypertension. When peptide is infused, at a rate that causes a moderate pressor effect, into the systemic blood flow of normal animals, an antidiuretic and antinatriuretic effect is obtained, in hypertensive animals--an increase of diuresis, natriuresis and a less distinct pressor effect are obtained. When angiotensin II is infused into the portal flow, a less distinct pressor and renal effect is seen in animals with renovascular hypertension. The operation of porto-caval transposition of the vessels results in a hypotensive effect in the animals with renovascular hypertension.     

Protein cleavage by transition metal complexes bearing amino acid substituents

In this report, we describe protein damage by a series of metal complexes that mediate the formation of hydroxyl radical. The protein targets used are bovine serum albumin (BSA) and carboxypeptidase A (CPA). BSA contains several electrostatic, hydrogen bonding and hydrophobic binding sites for potential interaction with the metal complexes, and CPA contains a specific phenylalanine binding site. The data presented in this study show that aromatic side chain damage and backbone cleavage occur to similar extents with all the complexes. Reasonable levels of backbone cleavage specificity can be attained with relatively few recognition elements, despite the fact that a diffusible radical mediates cleavage. Incorporation of additional recognition elements can enlarge the set of cleavage sites. We show that the chemical environment of the cleavage reaction, manipulated by using different buffers, can dramatically affect the outcome of the cleavage reaction. Our work suggests that backbone cleavage site is determined by three factors: the binding sites of the metal complexes, the role of reactive sites on the protein backbone, and the influence of the chemical environment on the reaction.     

The effect of dietary fat content on amino acid digestibility in young pigs

Studies were carried out with 12 pigs (Yorkshire x Landrace) to determine the effect of dietary fat content on amino acid digestibility. The pigs were weaned at 21 d of age and fitted with a simple T-cannula at the distal ileum at 27 or 28 d of age. After a 7-d recuperation period, the pigs were fed one of four isonitrogenous cornstarch-based soybean meal diets (22.5% CP) containing 3.2, 6.2, 9.2, or 12.2% canola oil according to a balanced two-period change-over design. The pigs were fed four times daily, equal amounts, at 6-h intervals. The diets were supplied at a rate of 5% of the average body weight that was determined at the initiation of the first (11.0 kg) and second (12.5 kg) experimental period. Each experimental period consisted of 10 d. Feces were collected for 48 h on d 6 and 7 and ileal digesta for 24 h during d 8, 9, and 10. Chromic oxide was used as digestibility marker. The apparent ileal digestibilities of most of the amino acids increased linearly (P < .05) with increasing dietary fat levels. There were differences (P < .05) in the ileal digestibilities of most of the amino acids between the diets containing 3.2 and 12.2% canola oil. Conversely, the dietary level of inclusion of canola oil did not affect (P > .05) the fecal amino acid digestibilities. The protein-sparing effect of additional canola oil inclusion results, in part, from an increase in ileal amino acid digestibility.     

Protein kinase inhibitors attenuate cardiac swelling-induced amino acid release in the rat

Rat Langendorff heart preparations have been used to study the efflux of cardiac amino acids into coronary artery perfusates during brief (5-min) periods of exposure to hyposmotic stress (70 mM NaCl). Coronary flow rates, heart rates and intra-aortic pressures were recorded. Amino acid levels were measured by high-performance liquid chromatography. Hyposmotic stress caused marked percentage increases in taurine, glutamate and aspartate levels in the coronary perfusate, with smaller increases in phosphoethanolamine, glycine and alanine and non-significant increases in serine and glutamine. Amino acid levels declined during reperfusion with isosmotic Krebs-Henseleit bicarbonate buffer. Inhibition of protein kinase C with chelerythrine chloride (5 microM) depressed the osmotically-induced release of aspartate, glutamate, taurine and glycine. The protein tyrosine kinase inhibitor, genistein, reduced the anisosmotic efflux of aspartate, glutamate, taurine and phosphoethanolamine. Lavendustin A, another inhibitor of tyrosine kinase, depressed the osmotically evoked release of aspartate, glutamate and taurine. These studies demonstrate the involvement of protein kinase C and tyrosine kinases in the efflux of amino acids from the osmotically challenged rat heart and imply that these enzymes are involved in the mechanisms responsible for volume regulation by cardiac cells.     

Modification of brain deoxyribonucleic acid base content with maturation in normal and malnourished rats

The mol percentage of 5-hydroxymethylcytosine is 2.2 times greater in the adult than in 2-day-old rat brain DNA. The concentration of 5-hydroxymethylcytosine falls in corresponding liver DNA preparations. This normal increase in brain 5-hydroxymethylcytosine is abolished in rats placed on an 8%-protein diet 5 days after birth.     

Effect of raw material source, processing systems, and processing temperatures on amino acid digestibility of meat and bone meals

Experiments were conducted to evaluate amino acid digestibility of 32 commercial meat and bone meals (MBM) varying in raw material source and produced in seven different commercial cooking systems and at two processing temperatures (low vs high) that differed by 15 to 20 C. Raw material sources included all beef, all pork, mixed species, and high bone MBM. True digestibilities of amino acids were determined using the precision-fed cecectomized rooster assay. Protein efficiency ratio (PER) of six MBM varying greatly in amino acid digestibility was determined with chicks fed 10% CP diets containing a MBM as the sole source of dietary protein. The 32 MBM samples averaged 53.2% CP, 2.73% Lys, 0.6% Cys, and 0.75% Met on a DM basis. True digestibility averaged 82% for Lys, 87% for Met, and 47% for Cys. True digestibilities of amino acids varied substantially among processing systems and temperatures, particularly for Lys and Cys. For example, Lys and Cys digestibility ranged from 68 to 92% and from 20 to 71%, respectively, among different MBM. The higher processing temperature generally yielded lower amino acid digestibility than did the low processing temperature. A smaller, less consistent, effect was observed for raw material source. The PER values of the six selected MBM varied from 0.97 to 2.68 and were highly correlated with amino acid digestibility. These results indicated that very high amino acid digestibility MBM can be produced in commercial rendering systems. However, differences in processing systems and temperatures can cause substantial variability in amino acid digestibilities.     

Neurotransmitter and amino acid analysis and ultrastructural observations of fetal brain cortex transplantation to adult rat brain under the effect of dexamethasone

OBJECTIVE: To conduct an investigation of fetal cortical tissue graft survival using transmission electron microscopy and analyzing neurotransmitters and amino acids and their function, with special reference to the effect of dexamethasone. METHODS: Transplantation of fetal cortical brain tissue to 100 adult Wistar albino rats weighing 170 to 220 g was performed. The rats were divided into three groups. Only transplantation of fetal cortical brain tissue was performed in the first group (n=36). In the second group (n=48), dexamethasone was administered in addition to fetal cortical tissue transplantation. The third group (n=16) was used as the surgical control group. The rats were allowed to live for 6 weeks and were then decapitated. The grafts were examined by electron microscopy. Additionally, quantitative analyses of the neurotransmitters and amino acids of the grafts were conducted using high-pressure liquid chromatography. RESULTS: Electron microscopic observations revealed that the grafts were still surviving at the end of the 6th week in both groups. However, in the group that received dexamethasone, neurons and their organelles were better developed than in the group that did not receive dexamethasone. Concommitantly, results of quantitative analysis in the dexamethasone group revealed statistically extremely significant higher amino acid values for glutamic acid, aspartic acid, beta-alanine, and lysine and significantly higher values for gamma-aminobutyric acid, glutamine, glycine, and serine when compared to the nondexamethasone group. CONCLUSION: Dexamethasone is effective in increasing the survival and in developing the ultrastructural and functional outcome of transplanted neurons in fetal grafts.     

Limiting amino acids in meat and bone and poultry by-product meals

In situ, digestion, and growth studies were conducted to evaluate four meat and bone meals and six poultry by-product meals as sources of escape protein and to predict the first-limiting amino acid for growing calves. Escape protein values, determined by 12-h in situ incubation, ranged from 41.7 to 51.0% of CP for meat and bone meals; poultry by-product meals ranged from 32.0 to 39.8%. True protein digestion in the gastrointestinal tract of lambs differed among protein sources (P < .05), ranging from 79 to 95%. In each of three growth trials, 60 steers (258 +/- 24, 241 +/- 23, and 230 +/- 16 kg for Trials 1, 2, and 3, respectively) were supplemented with 4 of the 10 protein sources along with a urea supplement. Protein sources were fed at 30, 40, 50, and 60% of the supplemental CP, with urea supplying the remainder. Protein efficiency differed among treatments ( P < .10), ranging from .61 to 1.55. Amino acid composition was determined for each protein source, and the individual metabolizable amino acids were regressed on the protein efficiency values. Escape protein values were correlated (R2 = .75) with protein efficiency but had a negative slope. Metabolizable methionine was the only amino acid moderately correlated (R2 = .40, slope = 1.9) to protein efficiency, whereas other amino acids either correlated poorly or had negative slopes. These data indicate that the protein value of meat and bone meal and poultry by-product meal is limited by the amount of metabolizable methionine they contain.     

The biological value of fats

Integral characteristics of animal development (weight increase, maturing of biological systems) used to date are not adequate to the requirements of detailed biological evaluation of dietary fats. The linoleic acid content in the dietary fat and the eicosatrienoic acid - eicosatetraenoic acid ratio (20:3/20:4 = HOLMAN coefficient) in the organism alone are also inadequate criteria. For this reason, the author attempted to establish metabolism-relevant law-like relationships between the fatty acid pattern of dietary fats and tissue lipids.     

Protein utilization of mechanically deboned meat by growing rats

The protein quality of mechanically deboned red meat was investigated using amino acid analysis, protein efficiency ratio and the slope ratio technique. Nine different meat products were studied utilizing Sprague-Dawley weanling albino rats. Protein quality of the mechanically deboned meat varied greatly with the amount of lean left on the bones prior to mechanical deboning. Deboned meat which contained more lean, and less collagen, was superior in protein quality to the deboned meat obtained from bones which contained less lean and more collagen. Total sulfur amino acids (cystine and methionine) and isoleucine were the most limiting amino acids in all nine of the meat products when compared with lactalbumin. The contents of total sulfur amino acids and isoleucine, as well as the ratio of essential amino acids to total amino acids, reflected the protein quality of the meat.     

The value of behavioral research on animals.

Presents facts documented by references to provide evidence regarding the value of behavioral research on animals. It is argued that attempts by radical animal activists to mislead humane people by repeatedly asserting such research is completely without any value and by other false statements are a disservice to animal welfare by deflecting funds from worthy activities. Some of the contributions of animal research have led to improvements in the welfare of animals. Animal research has also led to advances in psychotherapy, especially behavior therapy and behavioral medicine; rehabilitation of neuromuscular disorders; understanding and alleviating effects of stress and pain; discovery and testing of drugs for treatment of anxiety, psychosis, and Parkinson's disease; knowledge about mechanisms of drug addiction, relapse, and damage to the fetus; and understanding the mechanisms of some deficits of memory that occur with aging. (3 p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Excitatory amino acid receptors and puberty

Glutamate is an important excitatory signal in the hypothalamus for the steroid-mediated preovulatory gonadotropin surge. Steroids may exert this action by regulating glutamate receptor levels or glutamate release, or both. Work in our laboratory found no changes in NMDA and kainate receptor binding in the hypothalamus of castrated or castrated plus steroid-replaced male and female rats. Likewise, we found that NMDA and kainate binding did not change over the onset of puberty in the female rat. A competitive quantitative RT-PCR assay using exogenous internal standards was used to measure NMDAR1, GluR1, and beta-actin mRNAs levels. NMDAR1 and GluR1 expression was examined in the preoptic hypothalamic area and in the medial basal hypothalamus at Postnatal Days 10, 15, 20, 25, 30, 32, 34, 36, 40, and 63. A transient increase in GluR1 mRNA levels in the preoptic hypothalamic area was observed on Day 20, with all other time points showing comparable levels. NMDAR1 levels in the POA and medial basal hypothalamus did not change significantly at any of the time points; in contrast, however, AMPA receptor binding levels were increased in the hypothalamus at the time of puberty in the female rat. Thus, in addition to the previously reported elevation of glutamate release rates in the hypothalamus at the time of puberty, AMPA receptors may also be elevated and play a role in mediating glutamate regulatory effects on the timing of puberty in the female rat.     

Loss of the signature six carboxyl amino acid tail from ovine interferon-tau does not affect biological activity

Interferon-tau (IFN-tau) is a type I IFN that is secreted from conceptuses of Bovidae (sheep, cattle, and related ruminant ungulates) for a few days during early pregnancy. It acts to prolong the life span of the corpus luteum. All secreted forms of IFN-tau, like the related IFN-omega, are 172 amino acids in length and differ from IFN-alpha and -beta by the presence of six additional amino acids at their carboxyl termini. The aim of this study was to determine whether this carboxyl tail was important for biological activity of IFN-tau, particularly for its antiluteolytic function in ewes. Full-length ovine IFN-tau (p3) and a mutated form truncated by six amino acids at its carboxyl terminal (p3Trn6, 166 amino acids) were produced in Escherichia coli. Both proteins had similar antiviral activities (2.12 +/- 0.92 x 10(8) IU/mg for p3; 1.96 +/- 0.58 x 10(8) IU/mg for p3Trn6) when tested on Madin-Darby bovine kidney (MDBK) cells. Antiproliferative activity, as measured on human Daudi cells by determining the protein concentration required to inhibit growth by 50%, was slightly higher (p < 0.05) for p3Trn6 (7.36 +/- 0.46 pM) than for p3 (13.99 +/- 0.85 pM). Most importantly, p3 and p3Trn6 were equally capable of prolonging the life span of the corpus luteum of nonpregnant ewes when the proteins were administered at doses of either 60 or 300 microg/day into the uterine lumen through indwelling uterine cannulae from Day 10 to Day 18 postestrus. Therefore, the carboxyl-terminal amino acid extension for IFN-tau does not appear to serve a functional role in the action of these proteins.