Respiration physiology.
Discontinued
Periodical
Pulmonary Medicine
Respiratory Physiological Phenomena
Publisher:
North Holland Publishing. Amsterdam : North Holland Publishing
Frequency: Fifteen no. a year, 1999-
Country: Netherlands
Language: English
Start Year:1966 - 2002
Identifiers
| ISSN: | 0034-5687 (Print) 0034-5687 (Linking) |
| NLM ID: | 0047142 |
| (DNLM): | R26400000(s) |
| (OCoLC): | 01763798 |
| Coden: | RSPYAK |
| LCCN: | 66-9902 |
| Classification: | W1 RE248H |
Respiratory resistance and compliance in the anaesthetized horse.
Respiration physiology
February 1, 1969
Volume 6, Issue 2 257-270 doi: 10.1016/0034-5687(69)90063-2
Mapleson WW, Weaver BM.Total compliance and lower respiratory resistance, that is, total respiratory resistance less upper airway resistance, have been measured during passive expiration in anaesthetized, intubated, completely relaxed animals, lying on their sides. Nine horses and one mule were studied.
Compliance was determined for each animal from the volumes expired after inflation of the lungs to various pressures. The mean compliance for the horses was 0.246 (S.D. 0.088) litre/cm H2O or 0.573 (S.D. 0.229) (ml/cm H2O)/kg body mass.
Resistance was measured in the course of passive expiration through an endotrac... Comparative aspects of the strength of pulmonary capillaries in rabbit, dog, and horse.
Respiration physiology
July 1, 1994
Volume 97, Issue 2 235-246 doi: 10.1016/0034-5687(94)90029-9
Birks EK, Mathieu-Costello O, Fu Z, Tyler WS, West JB.In previous studies of rabbit and dog lung, we demonstrated stress failure of pulmonary capillaries at high transmural pressures (Ptm). The Ptm necessary to elicit stress failure was 40 cmH2O higher in dog than rabbit, and the total blood-gas barrier (BGB) thickness was greater in dog than rabbit. This suggests that stress failure may be related to BGB thickness, and is consistent with the Laplace relationship which states that wall stress is proportional to capillary radius but inversely proportional to wall thickness. In the present studies, we compared BGB thickness and an index of capillar... Read More
15
In vivo determination of surface tension in the horse trachea and in vitro model studies.
Respiration physiology
July 1, 1997
Volume 109, Issue 1 81-93 doi: 10.1016/s0034-5687(97)84032-7
Im Hof V, Gehr P, Gerber V, Lee MM, Schürch S.We measured the surface tension in the trachea of the non-anaesthetised horse from the spreading behaviour of fluid drops, using videotracheoscopy. To do this, we placed small oil drops onto the tracheal wall with a thin Teflon tubing inserted into a videocolonoscope used in humans. Either 5 ml of saline (control) or 5 ml of bovine lipid extract surfactant (BLES) at 4 mg/ml were administered. Tracheal surface tension was 31.9 +/- 0.54 mN/m (Mean +/- SEM, n = 30) in the control experiments and 24.5 +/- 0.51 mN/m (Mean +/- SEM, n = 21) in the entire trachea after the administration of BLES. Thes... Read More
15
Rate at which CO replaces O2 from O2Hb in red cells of different species.
Respiration physiology
June 1, 1969
Volume 7, Issue 1 43-63 doi: 10.1016/0034-5687(69)90068-1
Holland RA.No abstract available Read More
13
Cardiorespiratory impact of the nitric oxide synthase inhibitor L-NAME in the exercising horse.
Respiration physiology
April 25, 2000
Volume 120, Issue 2 151-166 doi: 10.1016/s0034-5687(00)00096-7
Kindig CA, Gallatin LL, Erickson HH, Fedde MR, Poole DC.To investigate the role of nitric oxide, NO, in facilitating cardiorespiratory function during exercise, five horses ran on a treadmill at speeds that yielded 50, 80 and 100% of peak pulmonary oxygen uptake (V(O(2)) peak) as determined on a maximal incremental test. Each horse underwent one control (C) and one (NO-synthase inhibitor; N(G)-L-nitro-arginine methyl ester (L-NAME), 20 mg/kg) trial in randomized order. Pulmonary gas exchange (open flow system), arterial and mixed-venous blood gases, cardiac output (Fick Principle), and pulmonary and systemic conductances were determined. L-NAME red... Read More
11
Effects of altered FIO2 on maximum VO2 in the horse.
Respiration physiology
August 1, 1996
Volume 105, Issue 1-2 123-134 doi: 10.1016/0034-5687(96)00044-8
Wagner PD, Erickson BK, Seaman J, Kubo K, Hiraga A, Kai M, Yamaya Y.Although the horse is considered an elite athlete with a specific VO2max some 2-4 times higher than man, maximal O2 transport is compromised both by moderately severe arterial desaturation and by failure to extract all O2 from blood perfusing exercising muscle. This prompted the present study to ascertain whether correction of arterial desaturation would proportionally augment VO2max and, if so, would O2 extraction behave in a manner predicted by diffusional transport limitation. Six two year old thoroughbreds were exercised to VO2max on a treadmill each on three separate occasions breathing g... Mechanics of breathing during strenuous exercise in Thoroughbred horses.
Respiration physiology
December 1, 1990
Volume 82, Issue 3 279-294 doi: 10.1016/0034-5687(90)90098-j
Art T, Anderson L, Woakes AJ, Roberts C, Butler PJ, Snow DH, Lekeux P.The changes induced by exercise on the mechanics of breathing, as well as the simultaneous changes occurring in arterial blood gas tensions and in respiratory gas exchange were investigated in 6 healthy thoroughbred horses, performing a treadmill exercise of increasing intensity. Respiratory airflow and tidal volume (VT) were measured with ultrasonic flowmeters. Pleural pressure changes were measured by an oesophageal balloon catheter. Gas concentration of the expired air was analysed with a mass spectrometer; the oxygen consumption (VO2) and the carbon dioxide output (VCO2) were computed brea... Morphometric estimation of pulmonary diffusion capacity in two horse lungs.
Respiration physiology
August 1, 1980
Volume 41, Issue 2 199-210 doi: 10.1016/0034-5687(80)90052-3
Gehr P, Erni H.The lungs of two half-bred geldings were fixed in situ by instillation of a glutaraldehyde solution into the airways during deep anaesthesia. The body weight of both animals was 510 kg and their average lung volume about 38 l. Stratified random samples from 22 regions were morphometrically analysed from electron microscopic films. Eighty-six per cent of the total lung volume was gas exchange parenchyma. It contained 26.9 l air space and 5.6 l interalveolar septa which were composed of equal parts of capillaries and tissue. The average alveolar and capillary surface areas were 2457 m2 and 1663 ... Mucus quality on horse tracheal epithelium: microscopic grading based on transparency.
Respiration physiology
January 1, 1997
Volume 107, Issue 1 67-74 doi: 10.1016/s0034-5687(96)02503-0
Gerber V, Gehr P, Straub R, Frenz M, King M, Im Hof V.The aim of this ex-vivo study on excised tracheas of healthy horses was to characterise the microscopic heterogeneity of mucus quality by a visual grading system based on transparency and to determine whether differences in mucus quality, assessed by a visual grading system, influence tracheal mucus velocity (TMV). Small pieces of each trachea were mounted into a humidified chamber under a microscope. Mucus quality was visually subdivided into four grades (MG) and ciliary beat frequency and TMV were determined. Mucus on excised horse tracheal epithelium does not form a homogenous layer. We obs... Rheological characteristics of horse blood: significance during exercise.
Respiration physiology
December 1, 1993
Volume 94, Issue 3 323-335 doi: 10.1016/0034-5687(93)90027-8
Fedde MR, Wood SC.When horses maximally exercise, splenic contraction and fluid movement out of the vascular compartment greatly increase the hematocrit (up to 0.70). We studied the in vitro rheological characteristics of blood from Thoroughbreds and Quarter Horses to determine the interaction of hematocrit and shear rate on apparent viscosity. We also compared the rheological characteristics of the blood before and after horses received furosemide, a drug commonly used to prevent exercise-induced pulmonary hemorrhage. Although the apparent viscosity of blood with a high hematocrit was high at low shear rates, ... Hypoxic helium breathing does not reduce alveolar-arterial PO2 difference in the horse.
Respiration physiology
June 1, 1995
Volume 100, Issue 3 253-260 doi: 10.1016/0034-5687(94)00138-p
Erickson BK, Seaman J, Kubo K, Hiraga A, Kai M, Yamaya Y, Wagner PD.In a previous study we evaluated the mechanism of alveolar-arterial PO2 (AaPO2) reduction when nitrogen is replaced with helium in normoxia (FIO2 = 0.21). The reduction in AaPO2 was not due to changes in VA/Q inequality, pulmonary O2 diffusing capacity, or cardiac output, but to more complete diffusion equilibration as a consequence of the higher ventilation and thus PAO2 (which reduced the average slope of the hemoglobin O2 dissociation curve (ODC), and thus enhanced diffusive equilibration). We hypothesized that hypoxic He/O2 breathing in contrast would not reduce the AaPO2 because PAO2 and ... Effects of racing and gender on viscoelastic properties of horse blood.
Respiration physiology
February 1, 1997
Volume 107, Issue 2 165-172 doi: 10.1016/s0034-5687(96)02518-2
Wood SC, Fedde MR.Splenic contraction in racing horses increases the hematocrit (hct), thereby increasing blood viscosity. We tested as to whether racing also affects the elastic properties of blood. Mares and geldings were studied for thus purpose. After racing, there was: (i) an increased erythrocyte count independent of gender and race distance (0.32 to 1.7 km): (ii) an increased mean erythrocyte volume in both sexes; (iii) an increased heterogeneity of RBC size in both sexes; (iv) an increased plasma fibrinogen concentration and erythrocyte sedimentation rate in both sexes; and (v) an increased elastic yiel... Cerebrospinal fluid alkalosis during high-altitude sojourn in unanesthetized ponies.
Respiration physiology
October 1, 1975
Volume 25, Issue 1 23-37 doi: 10.1016/0034-5687(75)90048-1
Orr JA, Bisgard GE, Forster HV, Buss DD, Dempsey JA, Will JA.Unanesthetized adult female ponies were studied near sea level (250 m) and during sojourns to 3400 m (N=6) and 4300 m (N=7) altitude. The pH, PCO2, and PO2 of arterial blood and pH and PCO2 of cerebrospinal fluid (CSF) were measured under conditions of acute (1 hr) and chronic (1-45 days) hypoxia. Cerebrospinal fluid was sampled from the cisterna magna of the awake pony and arterial blood withdrawn from an indwelling arterial catheter. In both groups of animals, PaCO2 decreased slightly after 1 hr of hypoxia (delta PaCO2= - 0.6 mm Hg at 3400 m; - 3.9 mm Hg at 4300 m), decreased further after 1... Unilateral hypoxic pulmonary vasoconstriction in the dog, pony and miniature swine.
Respiration physiology
September 1, 1991
Volume 85, Issue 3 355-369 doi: 10.1016/0034-5687(91)90074-s
Elliott AR, Steffey EP, Jarvis KA, Marshall BE.The hypoxic pulmonary vasoconstrictor response to unilateral hypoxia was analyzed in pentobarbital anesthetized dogs (n = 5), miniature swine (n = 5), and ponies (n = 5). The left and right lungs (LL, RL) were separately ventilated with the LL exposed to inspired oxygen concentrations (CIO2) of 100%, 12%, 8% or 4%, while the RL always received a CIO2 = 100%. Pulmonary blood flow distribution was measured using 15 microns radioactive microspheres. LL PAO2, and percent pulmonary blood flow diversion (%FD) were calculated at each CIO2. At CIO2 of 4% there were significant differences (P greater t... Rate of O2 dissociation from O2Hb and relative combination rate of CO and O2 in mammals at 37 degrees C.
Respiration physiology
June 1, 1969
Volume 7, Issue 1 30-42 doi: 10.1016/0034-5687(69)90067-x
Holland RA.No abstract available The effect of exercise on diaphragmatic activation in horses.
Respiration physiology
October 1, 1996
Volume 106, Issue 1 35-46 doi: 10.1016/0034-5687(96)00058-8
Ainsworth DM, Eicker SW, Nalevanko ME, Ducharme NG, Hackett RP, Snedden K.Horses chronically-instrumented with costal diaphragmatic electromyographic electrodes were studied during exercise while unencumbered by a breathing mask. Exercise-associated changes in esophageal (Pes), gastric (Pga) and transdiaphragmatic (Pdi) pressures were measured and related to diaphragmatic electromyographic activity (CS EMG) and to left forelimb impact. In all breaths examined, CS EMG always coincided with decrements in Pes. For all exercise trials, linear increases in CS EMG, Pga and Pdi and linear decreases in Pes, as a function of exercise intensity, always occurred. During all ga... Training and exercise change respiratory properties of blood in race horses.
Respiration physiology
May 1, 1977
Volume 29, Issue 3 315-325 doi: 10.1016/0034-5687(77)90006-8
Lykkeboe G, Schugaard H, Johansen K.Effects of training and exercise on blood respiratory properties were investigated in standard-bred race horses. Training caused an increase in the circulating O2 capacity at rest from 18.4 to 21.0 vol%, and in the O2 capacity during exercise from 24.9 to 30.3 vol%. An increase in the in vitro oxygen affinity [P50(PH 7.4, 37.9 degrees C)] of about 2 mm Hg correlated with a decrease in the red cell concentration of 2,3-diphosphoglycerate (DPG) from 6.35 mM-1-1(E), erythrocytes. Trained horses also showed an acute lowering of the red cell DPG concentration after maximal exercise. The physiologic... Pulmonary-locomotory interactions in exercising dogs and horses.
Respiration physiology
January 4, 1998
Volume 110, Issue 2-3 287-294 doi: 10.1016/s0034-5687(97)00094-7
Ainsworth DM, Smith CA, Eicker SW, Ducharme NG, Henderson KS, Snedden K, Dempsey JA.In exercising quadrupeds, limb movement is often coupled with breathing frequency. This finding has lead some investigators to conclude that locomotory forces, associated with foot plant, abdominal visceral displacements or lumbo-sacral flexion, are the primary determinants of airflow generation. Analysis of respiratory muscle electrical activation (EMG) and contraction profiles in chronically instrumented dogs and horses, along with measurements of esophageal pressure (Pes) changes and limb movements, provide evidence that each breath during the exercise hyperpnea is determined by respiratory... In vitro responses of equine small airways and lung parenchyma.
Respiration physiology
August 1, 1997
Volume 109, Issue 2 167-176 doi: 10.1016/s0034-5687(97)00053-4
Olszewski MA, Robinson NE, Derksen FJ.In vitro responses of equine small peripheral airways (SA) and lung parenchyma (LP) were studied. We examined their contractile and relaxant responses and investigated effects of histamine, and endogenous prostanoids as these mediators may play a role in development or recurrent airway obstruction in horses (heaves). SA and LP electrical field stimulation (EFS) induced nearly maximal and partial frequency-dependent contractions, respectively. These contractions were virtually abolished in SA but only partially inhibited in LP by atropine (ATR) and tetrodotoxin (TTX). Methacholine (MCh) contrac... Regional distribution of brain blood flow during maximal exertion in splenectomized ponies.
Respiration physiology
April 1, 1987
Volume 68, Issue 1 77-84 doi: 10.1016/0034-5687(87)90078-8
Manohar M.It has been reported in exercising ponies that O2 supply to all regions of the brain increased primarily due to a large increment in CaO2 and it was implied that this may reflect a generalized increase in brain metabolism during strenuous exercise. Splenectomy ameliorates the rise in CaO2 observed with exercise in ponies. Thus, the objective of the present study was to examine changes in regional brain blood flow and O2 supply of splenectomized ponies with sub-maximal and maximal exercise and to compare these data with previous observations in normal ponies. It was reasoned that in the absence... Stride length and respiratory tidal volume in exercising thoroughbred horses.
Respiration physiology
July 1, 1993
Volume 93, Issue 1 51-56 doi: 10.1016/0034-5687(93)90067-k
Butler PJ, Woakes AJ, Anderson LS, Roberts CA, Marlin DJ.The purpose of this study was to test the hypothesis that locomotor-respiratory coupling in horses may provide a basis for the appropriate matching of lung ventilation to running speed and metabolic power. This was achieved by determining the effect on respiratory frequency and tidal volume in thoroughbred horses of changing running speed while maintaining a constant metabolic demand by also varying the incline of the treadmill. This procedure was performed at three different speeds at two different levels of metabolic rate. It appears that, in response to metabolic demands which are not direc... Gene transfer by adenovirus in smooth muscle cells.
Respiration physiology
August 1, 1996
Volume 105, Issue 1-2 155-162 doi: 10.1016/0034-5687(96)00016-3
Yu MF, Ewaskiewicz JI, Adda S, Bailey K, Harris V, Sosnoski D, Tomasic M, Wilson J, Kotlikoff MI.We report adenovirus-mediated gene transfer into airway smooth muscle cells in cultured cells and organ-cultured tracheal segments. Incubation of cultured rat tracheal myocytes with virus (5 x 10(8) pfu/ml) for 6 h resulted in beta-galactosidase expression in 94.8 +/- 2.5% of cells (n = 4). Following incubation of thin (less than 200 microns diameter) equine trachealis muscle segments with virus in organ culture (5 x 10(8)-5 x 10(10) pfu/ml) the average expression of the Lac Z gene was approximately 19 +/- 10% (n = 9). Expression was markedly improved, however, in segments from neonatal rats (... Respiratory muscle recruitment in awake ponies during exercise and CO2 inhalation.
Respiration physiology
December 1, 1991
Volume 86, Issue 3 315-332 doi: 10.1016/0034-5687(91)90103-p
Gutting SM, Forster HV, Lowry TF, Brice AG, Pan LG.We measured respiratory muscle electromyograms (EMG), inspiratory (I) and expiratory (E) airflow patterns and functional residual capacity (FRC) in six ponies at rest, during treadmill walking at 1.8 mph-5, 10, and 15% grades, and during 2, 4, and 6% CO2 inhalation. There were several similarities in the responses to exercise and CO2 inhalation. The shapes of the I and E flow patterns were not changed appreciably from the respective control patterns during either condition. Mean diaphragm EMG increased from control (P less than 0.05) at 1.8 mph-10 and 15% grades, and during 4 and 6% inhalation... Cardiac output but not high pulmonary artery pressure varies with FIO2 in exercising horses.
Respiration physiology
January 1, 1993
Volume 91, Issue 1 83-97 doi: 10.1016/0034-5687(93)90091-n
Pelletier N, Leith DE.Horses have high mean pulmonary artery pressure (Ppa) both at rest and during exercise (approximately 30 and > or = 80 mmHg, respectively). The mechanisms are unknown. To see if hypoxic pulmonary vasoconstriction (HPV) plays a role, we compared pulmonary artery pressure-flow (Ppa-Q) curves when inspired O2 fraction (FIO2) was 0.16, 0.21, and 0.30, in 5 normal Thoroughbred horses standing quietly and while galloping at 10 and 14 m/sec on a level treadmill. We calculated O2 consumption (VO2) from measurements of respired gas composition and flow, and calculated Q from VO2 and measurements of ... Oxygen deficit-oxygen debt relationships in ponies during submaximal treadmill exercise.
Respiration physiology
November 1, 1987
Volume 70, Issue 2 251-263 doi: 10.1016/0034-5687(87)90055-7
Powers SK, Beadle RE, Lawler J, Thompson D.The O2 deficit-O2 debt relationship in ponies was examined at two levels of treadmill exercise. Five healthy ponies exercised for 8 min at two work rates (WR):(1) 50 m/min at 6% grade and (2) 70 m/min at 12% grade. The O2 deficit and O2 debt were calculated using open-circuit measurement of pulmonary gas exchange during the transition from rest to steady-state exercise and during recovery from exercise. The O2 deficit was significantly lower (P less than 0.05) than the O2 debt at each of the two work rates. The means (+/- SEM) for the deficit and the O2 debt, respectively, in liters were: (1) ... Independent modulation of horse airway smooth muscle by epithelium and prostanoids.
Respiration physiology
September 1, 1993
Volume 93, Issue 3 279-288 doi: 10.1016/0034-5687(93)90074-k
Yu M, Robinson NE, Wang Z, Derksen FJ.The effects of epithelial removal and cyclooxygenase inhibition on contractions induced by exogenous acetylcholine (ACh) and electrical field stimulation (EFS) were evaluated in horse tracheal strips and bronchial rings. Epithelial removal potentiated the response to ACh but had no influence on the response to EFS. The effect of epithelial removal was not altered by pretreating the tissues with meclofenamate, a cyclooxygenase inhibitor. In trachealis strips, meclofenamate augmented contractions induced by EFS but not by ACh. In bronchial rings, meclofenamate augmented EFS-induced contraction t... Excitatory prejunctional beta 2-adrenoceptor distribution within equine airway cholinergic nerves.
Respiration physiology
October 1, 1996
Volume 106, Issue 1 81-90 doi: 10.1016/0034-5687(96)00062-x
Zhang XY, Zhu FX, Robinson NE.We examined the effect of activation of beta 2-adrenoceptor (AR) by isoproterenol (ISO) on acetylcholine (ACh) release evoked by electrical field stimulation (EFS: 20 V, 0.5 Hz, 0.5 msec) from cholinergic nerves in five regions of equine airways. We also tested if the effect of ISO was dependent on epithelium or prostanoids by examining the effect of ISO on ACh release in the presence and absence of epithelium or cyclooxygenase inhibition. Trachealis strips or bronchial rings were preincubated for 60 min with 10(-7) M atropine, 10(-6) M neostigmine, and 10(-5) M guanethidine. The ACh amount wa... Modulation of equine tracheal smooth muscle contractility by epithelial-derived and cyclooxygenase metabolites.
Respiration physiology
April 1, 1991
Volume 84, Issue 1 105-114 doi: 10.1016/0034-5687(91)90022-b
Tessier GJ, Lackner PA, O'Grady SM, Kannan MS.The role of epithelium in the modulation of contractile responses to electrical field stimulation (EFS), acetylcholine (ACh), and KCl were studied in vitro in strips of equine tracheal smooth muscle (TSM). EFS with 0.5 ms pulses of voltage (70 V) resulted in frequency dependent contractions of equine TSM that were sensitive to tetrodotoxin (TTX) and atropine. In TSM without epithelium, preincubation with indomethacin significantly potentiated contractile responses to EFS. The potentiating effect of indomethacin on EFS contractions was abolished by the addition of 3 nM prostaglandin E2 (PGE2). ... Regional brain blood flow and O2 delivery during severe exertion in the pony.
Respiration physiology
June 1, 1986
Volume 64, Issue 3 339-349 doi: 10.1016/0034-5687(86)90127-1
Manohar M.Regional distribution of brain blood flow (radionuclide labelled 15 microns diameter microspheres) and O2 supply were studied in 11 healthy adult grade ponies at rest and during severe exercise (SE) performed on a treadmill (heart rate = 220 +/- 4 beats X min-1; VO2 = 126 +/- 9 ml X min-1 X kg-1). During SE, the mean aortic pressure increased to 169 +/- 4 mm Hg and the pHa, PaCO2 and PaO2 were 7.213 +/- 0.010, 30 +/- 1 mm Hg and 85 +/- 4 mm Hg, respectively. The hemoglobin concentration increased by 59.6% with SE. Whereas blood flow increased in the cerebellar gray matter (96%), pons (39.5%) a... Respiratory resistance and compliance in the anaesthetized horse.
Respiration physiology
February 1, 1969
Volume 6, Issue 2 257-270 doi: 10.1016/0034-5687(69)90063-2
Mapleson WW, Weaver BM.Total compliance and lower respiratory resistance, that is, total respiratory resistance less upper airway resistance, have been measured during passive expiration in anaesthetized, intubated, completely relaxed animals, lying on their sides. Nine horses and one mule were studied.
Compliance was determined for each animal from the volumes expired after inflation of the lungs to various pressures. The mean compliance for the horses was 0.246 (S.D. 0.088) litre/cm H2O or 0.573 (S.D. 0.229) (ml/cm H2O)/kg body mass.
Resistance was measured in the course of passive expiration through an endotrac... Respiratory mechanics of the horse during the first year of life.
Respiration physiology
January 1, 1994
Volume 95, Issue 1 21-41 doi: 10.1016/0034-5687(94)90045-0
Koterba AM, Wozniak JA, Kosch PC.This study investigated the developmental changes in the mechanical properties of the respiratory system in growing horses. Pulmonary mechanics and lung volumes were serially measured in anesthetized foals during the first year of life. Quasi-static pressure-volume curves were generated, and functional residual capacity (FRC) was measured using a closed nitrogen equilibration technique. At birth, chest wall compliance normalized to body weight was substantially less than that reported in other less precocious newborn species, while lung compliance normalized to body weight was similar to value...