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Author Steinhoff, H.J.; Schrader, J.; Schlitter, J. openurl 
  Title Temperature-jump studies and polarized absorption spectroscopy of methemoglobin-thiocyanate single crystals Type Journal Article
  Year 1992 Publication Biochimica et Biophysica Acta Abbreviated Journal Biochim Biophys Acta  
  Volume 1121 Issue 3 Pages 269-278  
  Keywords Animals; Crystallization; Horses; Kinetics; Methemoglobin/*chemistry; Solutions; Spectrum Analysis; Temperature; Thiocyanates/*chemistry  
  Abstract Association equilibria and association kinetics of the thiocyanate binding reaction to methemoglobin in single crystals and solution are studied using temperature-jump technique and polarized absorption spectroscopy. Different kinetic constants are found for the reaction in solution and crystal phase for the alpha- and beta-subunits of the methemoglobin tetramer. The reduction of the reactivity of the alpha- and beta-subunits in crystalline phase is 6-fold and 2.4-fold, respectively, compared to the values found in solution. The intramolecular binding reaction of the N epsilon of the distal histidine E7 which is observed in methemoglobin in solution cannot be detected in single crystals. Our results suggest that crystallization of hemoglobin has little influence on small-scale structural fluctuations which are necessary for ligands to get to the binding sites and large-scale structural motions are suppressed.  
  Address Institut fur Biophysik, Ruhr-Universitat Bochum, Germany  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0006-3002 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:1627604 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3800  
Permanent link to this record
 

 
Author Thiel, D.; Jenni-Eiermann, S.; Palme, R. doi  openurl
  Title Measuring corticosterone metabolites in droppings of capercaillies (Tetrao urogallus) Type Journal Article
  Year 2005 Publication Annals of the New York Academy of Sciences Abbreviated Journal Ann N Y Acad Sci  
  Volume 1046 Issue Pages 96-108  
  Keywords Adrenocorticotropic Hormone/administration & dosage/analysis/metabolism; Animals; Circadian Rhythm; Corticosterone/administration & dosage/*analysis/*metabolism; Feces/*chemistry; Female; Freezing; Galliformes/*metabolism; Male; Reproducibility of Results; Sex Factors; Temperature; Time Factors; Tritium/diagnostic use  
  Abstract The capercaillie (Tetrao urogallus), the largest grouse species in the world, is decreasing in numbers in major parts of its distribution range. Disturbances by human outdoor activities are discussed as a possible reason for this population decline. An indicator for disturbances is the increase of the glucocorticoid corticosterone, a stress hormone, which helps to cope with life-threatening situations. However, repeated disturbances might result in a long-term increase of the basal corticosterone concentration, which can result in detrimental effects like reduced fitness and survival of an animal. To measure corticosterone metabolites (CMs) noninvasively in the droppings of free-living capercaillies, first an enzyme immunoassay (EIA) in captive birds had to be selected and validated. Therefore, the excretion pattern of intravenously injected radiolabeled corticosterone was determined and 3H metabolites were characterized. High-performance liquid chromatography (HPLC) separations of the samples containing peak concentrations revealed that corticosterone was extensively metabolized. The HPLC fractions were tested in several EIAs for glucocorticoid metabolites. The physiological relevance of this method was proved after pharmacological stimulation of the adrenocortical activity. Only the recently established cortisone assay, measuring CMs with a 3,11-dione structure, detected an expressed increase of concentrations following ACTH stimulation. To set up a sampling protocol suited for the field, we examined the influence of various storage conditions and time of day on concentrations of CMs.  
  Address Swiss Ornithological Institute, 6204 Sempach, Switzerland. dominik.thiel@vogelwarte.ch  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0077-8923 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:16055846 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4079  
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Author Natalini, C.C.; Robinson, E.P. openurl 
  Title Effects of epidural opioid analgesics on heart rate, arterial blood pressure, respiratory rate, body temperature, and behavior in horses Type Journal Article
  Year 2003 Publication Veterinary Therapeutics : Research in Applied Veterinary Medicine Abbreviated Journal Vet Ther  
  Volume 4 Issue 4 Pages 364-375  
  Keywords 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/administration & dosage/pharmacology; Alfentanil/administration & dosage/pharmacology; Analgesics, Opioid/administration & dosage/*pharmacology; Anesthesia, Epidural/*veterinary; Animals; Behavior, Animal/drug effects; Blood Pressure/drug effects; Body Temperature/drug effects; Butorphanol/administration & dosage/pharmacology; Cross-Over Studies; Female; Heart Rate/drug effects; Horses/*physiology; Injections, Epidural/veterinary; Male; Morphine/administration & dosage/pharmacology; Respiration/drug effects; Tramadol/administration & dosage/pharmacology  
  Abstract Heart rate, arterial blood pressures, respiratory rate, body temperature, and central nervous system excitement were compared before and after epidural administration of morphine (0.1 mg/kg), butorphanol (0.08 mg/kg), alfentanil (0.02 mg/kg), tramadol (1.0 mg/kg), the k-opioid agonist U50488H (0.08 mg/kg), or sterile water using an incomplete Latin square crossover design in five conscious adult horses. Treatments were administered into the first intercoccygeal epidural space. Significant (P <.05) reductions in respiratory rate were detected after epidural administration of morphine, alfentanil, U50488H, and sterile water. Additionally, significant (P <.05) head ptosis was observed within the first hour after administration of morphine, U50488H, and tramadol, but neither of these changes appeared to be of clinical significance. No treatment-related changes in motor activity or behavior were observed.  
  Address Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1528-3593 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:15136978 Approved no  
  Call Number Serial 1902  
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Author Miksovska, J.; Larsen, R.W. openurl 
  Title Photothermal studies of pH induced unfolding of apomyoglobin Type Journal Article
  Year 2003 Publication Journal of Protein Chemistry Abbreviated Journal J Protein Chem  
  Volume 22 Issue 4 Pages 387-394  
  Keywords Acoustics; Animals; Apoproteins/*chemistry/metabolism; Circular Dichroism; Horses; Myocardium/chemistry; Myoglobin/*chemistry/metabolism; Photolysis; Protein Conformation/radiation effects; Protein Denaturation/radiation effects; *Protein Folding; Temperature; Thermodynamics  
  Abstract Conformational dynamic and enthalpy changes associated with pH induced unfolding of apomyoglobin were studied using photoacoustic calorimetry and photothermal beam deflection methods. The transition between the native state and the I intermediate was induced by a nanosecond pH jump from o-nitrobenzaldehyde photolysis. Deconvolution of photoacoustic waves indicates two kinetic processes. The fast phase (T < 50 ns) is characterized by a volume expansion of 8.8 ml mol(-1). This process is followed by a volume contraction of about -22 ml mol(-1) (tau approximately 500 ns). Photothermal beam deflection measurements do not reveal any volume changes on the time scale between approximately 100 micros and 5 ms. We associate the volume contraction with structural changes occurring during the transition between the native state and the I intermediate. The lack of any processes on the ms time scale may indicate the absence of structural events involving larger conformational changes of apomyoglobin after the pH jump.  
  Address Department of Chemistry, University of South Florida, Tampa, Florida 33620, USA  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0277-8033 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:13678303 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3780  
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Author Gulotta, M.; Rogatsky, E.; Callender, R.H.; Dyer, R.B. openurl 
  Title Primary folding dynamics of sperm whale apomyoglobin: core formation Type Journal Article
  Year 2003 Publication Biophysical Journal Abbreviated Journal Biophys J  
  Volume 84 Issue 3 Pages 1909-1918  
  Keywords Animals; Apoproteins/*chemistry; Crystallography/*methods; Horses; Myocardium/chemistry; Myoglobin/*chemistry; Protein Conformation; *Protein Folding; Species Specificity; Structure-Activity Relationship; Temperature; Whales  
  Abstract The structure, thermodynamics, and kinetics of heat-induced unfolding of sperm whale apomyoglobin core formation have been studied. The most rudimentary core is formed at pH(*) 3.0 and up to 60 mM NaCl. Steady state for ultraviolet circular dichroism and fluorescence melting studies indicate that the core in this acid-destabilized state consists of a heterogeneous composition of structures of approximately 26 residues, two-thirds of the number involved for horse heart apomyoglobin under these conditions. Fluorescence temperature-jump relaxation studies show that there is only one process involved in Trp burial. This occurs in 20 micro s for a 7 degrees jump to 52 degrees C, which is close to the limits placed by diffusion on folding reactions. However, infrared temperature jump studies monitoring native helix burial are biexponential with times of 5 micro s and 56 micro s for a similar temperature jump. Both fluorescence and infrared fast phases are energetically favorable but the slow infrared absorbance phase is highly temperature-dependent, indicating a substantial enthalpic barrier for this process. The kinetics are best understood by a multiple-pathway kinetics model. The rapid phases likely represent direct burial of one or both of the Trp residues and parts of the G- and H-helices. We attribute the slow phase to burial and subsequent rearrangement of a misformed core or to a collapse having a high energy barrier wherein both Trps are solvent-exposed.  
  Address Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, USA. gulotta@aecom.yu.edu  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0006-3495 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:12609893 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3783  
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Author Bayley, P.; Martin, S.; Anson, M. openurl 
  Title Temperature-jump circular dichroism: observation of chiroptical relaxation processes at millisecond time resolution Type Journal Article
  Year 1975 Publication Biochemical and Biophysical Research Communications Abbreviated Journal Biochem Biophys Res Commun  
  Volume 66 Issue 1 Pages 303-308  
  Keywords *Alcohol Oxidoreductases/metabolism; Animals; Circular Dichroism; Horses; Kinetics; Liver/enzymology; Mathematics; Protein Conformation; Temperature; Time Factors  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0006-291X ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:1172440 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3816  
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Author Marlin, D.J.; Schroter, R.C.; White, S.L.; Maykuth, P.; Matthesen, G.; Mills, P.C.; Waran, N.; Harris, P. openurl 
  Title Recovery from transport and acclimatisation of competition horses in a hot humid environment Type Journal Article
  Year 2001 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J  
  Volume 33 Issue 4 Pages 371-379  
  Keywords Acclimatization/*physiology; Animals; Body Temperature; Body Weight; Breeding; Feeding Behavior; Female; Heart Rate; Heat; Heat Stroke/prevention & control/veterinary; Horse Diseases/prevention & control; Horses/*physiology; Humidity; Male; Respiration; Sports; *Transportation; Tropical Climate  
  Abstract The aims of the present field-based study were to investigate changes in fit horses undergoing acclimatisation to a hot humid environment and to provide data on which to base recommendations for safe transport and acclimatisation. Six horses (age 7-12 years) were flown from Europe to Atlanta and underwent a 16 day period of acclimatisation. Exercise conditions during acclimatisation (wet bulb globe temperature index 27.6+/-0.0 [mean +/- s.e.]) were more thermally stressful compared with the European climate from which the horses had come (22.0+/-1.8, P<0.001). Following the flight, weight loss was 4.1+/-0.8% bodyweight and took around 7 days to recover. Water intake during the day was significantly increased (P<0.05) compared with night during acclimatisation. Daily mean exercise duration was 72+/-12 min and the majority of work was performed with a heart rate below 120 beats/min. Respiratory rate (fR) was increased (P<0.05) throughout acclimatisation compared with in Europe, but resting morning (AM) and evening (PM) rectal temperature (TREC), heart rate (fC) and plasma volume were unchanged. White blood cell (WBC) count was significantly increased at AM compared with in Europe on Days 4 and 10 of acclimatisation (P<0.01), but was not different by Day 16. In conclusion, horses exposed to hot humid environmental conditions without prior acclimatisation are able to accommodate these stresses and, with appropriate management, remain fit and clinically healthy, without significant risk of heat illness or heat-related disorders, provided they are allowed sufficient time to recover from transport, acclimatisation is undertaken gradually and they are monitored appropriately.  
  Address Centre for Equine Studies, Animal Health Trust, Newmarket, Suffolk, UK  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0425-1644 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:11469770 Approved no  
  Call Number refbase @ user @ Serial 1917  
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Author McCutcheon, L.J.; Geor, R.J. openurl 
  Title Influence of training on sweating responses during submaximal exercise in horses Type Journal Article
  Year 2000 Publication Journal of Applied Physiology (Bethesda, Md. : 1985) Abbreviated Journal J Appl Physiol  
  Volume 89 Issue 6 Pages 2463-2471  
  Keywords Animals; Body Fluids/metabolism; Body Temperature; Body Weight; Environment; Female; Horses/*physiology; Ions; Male; Motor Activity/*physiology; Oxygen Consumption; Physical Conditioning, Animal/*physiology; Sweat/chemistry; Sweating/*physiology; Time Factors  
  Abstract Sweating responses were examined in five horses during a standardized exercise test (SET) in hot conditions (32-34 degrees C, 45-55% relative humidity) during 8 wk of exercise training (5 days/wk) in moderate conditions (19-21 degrees C, 45-55% relative humidity). SETs consisting of 7 km at 50% maximal O(2) consumption, determined 1 wk before training day (TD) 0, were completed on a treadmill set at a 6 degrees incline on TD0, 14, 28, 42, and 56. Mean maximal O(2) consumption, measured 2 days before each SET, increased 19% [TD0 to 42: 135 +/- 5 (SE) to 161 +/- 4 ml. kg(-1). min(-1)]. Peak sweating rate (SR) during exercise increased on TD14, 28, 42, and 56 compared with TD0, whereas SRs and sweat losses in recovery decreased by TD28. By TD56, end-exercise rectal and pulmonary artery temperature decreased by 0.9 +/- 0.1 and 1.2 +/- 0.1 degrees C, respectively, and mean change in body mass during the SET decreased by 23% (TD0: 10.1 +/- 0.9; TD56: 7.7 +/- 0.3 kg). Sweat Na(+) concentration during exercise decreased, whereas sweat K(+) concentration increased, and values for Cl(-) concentration in sweat were unchanged. Moderate-intensity training in cool conditions resulted in a 1.6-fold increase in sweating sensitivity evident by 4 wk and a 0.7 +/- 0.1 degrees C decrease in sweating threshold after 8 wk during exercise in hot, dry conditions. Altered sweating responses contributed to improved heat dissipation during exercise and a lower end-exercise core temperature. Despite higher SRs for a given core temperature during exercise, decreases in recovery SRs result in an overall reduction in sweat fluid losses but no change in total sweat ion losses after training.  
  Address Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada N1G 2W1. jmccutch@uoguelph.ca  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 8750-7587 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:11090603 Approved no  
  Call Number refbase @ user @ Serial 1922  
Permanent link to this record
 

 
Author Hagen, S.J.; Eaton, W.A. doi  openurl
  Title Two-state expansion and collapse of a polypeptide Type Journal Article
  Year 2000 Publication Journal of Molecular Biology Abbreviated Journal J Mol Biol  
  Volume 301 Issue 4 Pages 1019-1027  
  Keywords Animals; Computer Simulation; Cytochrome c Group/*chemistry/*metabolism; Horses; Kinetics; Lasers; Models, Chemical; Peptides/*chemistry/*metabolism; Protein Conformation; Protein Denaturation; *Protein Folding; Spectrometry, Fluorescence; Temperature; Thermodynamics  
  Abstract The initial phase of folding for many proteins is presumed to be the collapse of the polypeptide chain from expanded to compact, but still denatured, conformations. Theory and simulations suggest that this collapse may be a two-state transition, characterized by barrier-crossing kinetics, while the collapse of homopolymers is continuous and multi-phasic. We have used a laser temperature-jump with fluorescence spectroscopy to measure the complete time-course of the collapse of denatured cytochrome c with nanosecond time resolution. We find the process to be exponential in time and thermally activated, with an apparent activation energy approximately 9 k(B)T (after correction for solvent viscosity). These results indicate that polypeptide collapse is kinetically a two-state transition. Because of the observed free energy barrier, the time scale of polypeptide collapse is dramatically slower than is predicted by Langevin models for homopolymer collapse.  
  Address Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Building 5, Bethesda, MD, 20892-0520, USA  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-2836 ISBN Medium  
  Area Expedition Conference  
  Notes (down) PMID:10966803 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3790  
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Author Morgan, K.; Funkquist, P.; Nyman, G. url  doi
openurl 
  Title The effect of coat clipping on thermoregulation during intense exercise in trotters Type Journal Article
  Year 2002 Publication Equine Veterinary Journal Abbreviated Journal Equine Veterinary Journal  
  Volume 34 Issue S34 Pages 564-567  
  Keywords horse; thermoregulation; heat loss; recovery; blood temperature; oxygen uptake  
  Abstract Summary The aim of this study was to study the physiological, especially thermoregulatory, responses during intense exercise in the clipped horse compared to the horse with winter coat. Six Standardbred trotters were studied before and after clipping. They performed an inclined incremental high intensity treadmill exercise test and were monitored during recovery. The clipped horse differed significantly (ANOVA) during exercise as compare to coated: less increase in central venous blood temperature, higher skin surface temperature, greater difference skin to ambient temperature and higher rate of nonevaporative heat loss. The clipped horse had significantly lower total cutaneous evaporative heat loss from walk to end of peak exercise and a shorter time for recovery for the respiratory rate using a paired t test. The clipped horse showed a tendency (P = 0.059) to decreased oxygen uptake during the stepwise increase in workload. We concluded that the clipped horse experienced less strain on the thermoregulatory system due to an enhanced heat loss. Some clipped horses in the study showed a more efficient power output; future studies with emphasis on respiration and oxygen demand are needed to explain this.  
  Address  
  Corporate Author Thesis  
  Publisher American Medical Association (AMA) Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0425-1644 ISBN Medium  
  Area Expedition Conference  
  Notes (down) doi: 10.1111/j.2042-3306.2002.tb05484.x Approved no  
  Call Number Equine Behaviour @ team @ Serial 6614  
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