Browsing by Subject "amino acids"
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Item Arginine and fetal growth in ovine models of intrauterine growth restriction(2009-05-15) Lassala, Arantzatzu LeticiaThis research was conducted to test the hypothesis that parenteralarginine supplementation is effective in enhancing birth weights of intrauterinegrowth restricted (IUGR) fetuses. Underfed and prolific ewes were used asexperimental models. The first study characterized the pharmacokinetics ofarginine and citrulline and assessed the potential of citrulline to serve as aprecursor for enhancing arginine availability in fetal and maternal plasma. Sixlate pregnant ewes and their fetuses were instrumented to access arterial andvenous circulations. Intravenous boluses of 155 mol of L-arginine-HCl or Lcitrullineper kg body weight were administered to each ewe. Administration ofcitrulline was more effective than arginine in achieving a sustained increase inconcentrations of arginine in maternal and fetal blood. Accordingly, theclearance rate of citrulline was lower and its biological half-life in maternal bloodgreater, when compared with arginine. The second experiment determined ifadministration of arginine to underfed ewes is effective in ameliorating orpreventing IUGR. Ewes were fed either 100% or 50% of the National ResearchCouncil recommended nutrient requirements for pregnant sheep. Between Day60 of pregnancy and parturition control-fed ewes received saline solution and underfed ewes received either saline solution or L-arginine-HCl solution (155mol of arginine/kg body weight) intravenously three times daily (n=5 / treatmentgroup). Birth weights of lambs were lower in saline-infused underfed ewes.There was no difference in birth weights of lambs from control-fed and argininetreatedunderfed ewes. The third experiment determined whether administrationof arginine could improve survival rates of lambs and enhance fetal growth inewes carrying multiple fetuses. Between Days 100 and 121 of pregnancy, ewesreceived an intravenous infusion of either saline solution (n= 14) or L-arginine-HCl solution (345 mol of arginine/kg body weight, n=20) three times daily.Parenteral administration of arginine increased the percentage of lambs bornalive and enhanced the birth weights of quadruplets. Collectively, these resultsindicate that 1) parenteral administration of arginine improves pregnancyoutcomes in underfed and prolific ewes; and 2) the use of arginine or citrullinemay have important implications for the design of an effective treatment forpreventing or ameliorating IUGR in mammals.Item Feeding specific amino acids to increase redberry juniper consumption by goats(2012-05-12) Steele, Diana; Steele, Diana Kay; Scott, Cody B.; Salisbury, Micheal W.; Whitney, Travis R.; Russell, Connie; Angelo State University. Department of Agriculture.Redberry juniper (Juniperus pinchotii Sudw.) is a chemically defended, invasive brush species in western states. Previous research has demonstrated that goats supplemented with escape protein sources will consume a higher volume of juniper. In this study I attempted to increase the intake of juniper by recently weaned, Boer-Spanish cross goats (n = 30) by randomly placing them into four treatments and a control, and supplementing each treatment group with one of the following amino acids: arginine, proline, leucine, and glutamine. Treatments did not have a significant effect on juniper intake (P > 0.05). All goats increased intake over time (P > 0.05). Goats exhibited significant weight gain over the course of the study (P < 0.05). Blood serum metabolites were within normal limits. Future studies on escape protein supplementation may provide a better understanding of small ruminant physiology in relationship to intake of juniper.Item Insect Herbivore Stoichiometry: The Effect of Macronutrient Quantity, Ratio, and Quality (Orthoptera: Acridae, Schistocerca americana)(2011-02-22) Boswell, Andrew William PayneThe field of ecological stoichiometry has been dominated by studies focusing on aquatic & benthic microinvertabrates with less attention given to herbivorous insects. These organisms rely on their food source(s) to supply all of the building blocks (elements) they need in order to complete their life cycle. Since insect herbivores do not have the same elemental composition as the plants they use for food the question arises; of how they go about building themselves. We investigated what happened when grasshoppers were fed diets with various macronutrient profiles, their total amounts, and when the protein quality varied. We discovered that under controlled conditions when using a high quality protein source that grasshoppers are able to maintain a strict level of elemental homeostasis, but that the elements directly related to manipulations made in the food seem to vary (carbon, which is associated with carbohydrates and nitrogen, associated with protein). We also discovered that when the quality of protein changes an immature grasshoppers elemental stoichiometry loses some of this strict homeostatic regulation.Item Radiolysis of Amino Acids: A Study Using Raman Spectroscopy, Ultraviolet-Visible Spectrophotometry and Electrospray Ionization Mass Spectrometry(2014-12-17) Lou, JijieAmino acids are basic components of proteins and play a critical role in the development and treatment of chronic diseases. Raman spectroscopy, as a non-destructive tool with little sample preparation, has been widely used in vitro and vivo studies. In the current study, twenty amino acids in solid state and aqueous/0.5 M hydrogen chloride (HCl) solution were previously irradiated to 10 kGy, 25 kGy and 50 kGy by electron beam and analyzed using Raman spectroscopy, ultraviolet-visible (UV-Vis) spectrophotometry and electrospray ionization mass spectrometry (ESI-MS). Raman spectroscopy revealed spectral signatures of radiolysis of amino acids which related to the specific molecular vibration could be used for non-invasive analysis of radiation damage in vivo. Correlation between the absorbed dose and absorbance of amino acids was modeled by exponential saturation to explain the nature of radical production during irradiation. The results from ESI-MS revealed the modification of molecules after radiation. The relative stability to radiolysis of twenty amino acids was estimated from the results of those three techniques and compared with previous work. The ability of three techniques to identify and analyze the effects of radiolysis of amino acids in solution was evaluated. This first attempt to combine these three techniques to explore the radiation effect on amino acids, is promising for the further application in vivo studies.