Respiration Kinetics Research Articles

The use of the Hellige Oxymonitor to study skin blood flow changes.

Transcutaneous oxygen tension is a flow related parameter. Detailed analysis of the physiology and physical chemistry of oxygen consumption and diffusion indicates that tcPO2 is not proportional to skin blood flow. Measurement of tcPO2 at 37 degrees C allows changes in skin blood flow to be clearly demonstrated and is of use in many areas of clinical medicine. Transcutaneous oxygen tension recorded using a polarographic oxygen electrode depends on skin blood flow, skin respiration, arterial oxygen concentration, temperature, skin and electrode permeability and the oxygen consumption of the electrode. Applying clearance principles, the relationship between blood flow, respiration and the difference between arterial and venous oxygen concentrations is well established. This has long been used to measure cardiac output, since the other three parameters are readily determined. Arterial saturation is normally greater than 95% of maximum in subjects without lung disease and it may thus be considered to be constant. Tissue respiration is independent of oxygen concentration when PO2 exceeds 2 mm Hg. If skin respiration is invariant at constant temperature, when the tissue oxygen tension exceeds 2 mm Hg, then blood flow is inversely proportional to the difference in concentration between arterial and venous blood. It has recently been directly shown that the inference that tissue respiration is independent of tissue blood flow is accurate. Correcting for the oxyhaemoglobin dissociation curve and for the deviation from zero order respiration kinetics when tissue PO2 less than 2 mm Hg, the relationship between venous oxygen tension and blood flow at 37 degrees C is shown when arterial oxygen concentration is constant (Figure 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of insulin secretion by energy metabolism in pancreatic B-cell mitochondria. Studies with a non-metabolizable leucine analogue

In mouse pancreatic islets the kinetics of insulin secretion and O2 uptake in response to the non-metabolizable leucine analogue (+/-)-BCH (2-endo- aminonorbornane -2-carboxylic acid) were compared. In addition, the fuel-mobilizing effect of (+/-)-BCH was studied with a mitochondrial fraction from islets. (1) Within 2 min 20 mM-(+/-)-BCH markedly enhanced insulin release or O2 consumption by islets respiring in the absence of exogenous fuels. During prolonged exposure to 20 mM-(+/-)-BCH secretion declined more rapidly than O2 uptake. (2) L-Glutamine (10 mM) prevented the decrease of both insulin release and O2 uptake of islets exposed to 20mM-(+/-)-BCH. During the second phase of insulin release in response to 20 mM-(+/-)-BCH + 10 mM-L-glutamine, kinetics of secretion and respiration correlated closely. (3) Initial peaks were consistently seen in the (+/-)-BCH-induced secretory profiles, but never in the respiratory profiles. (4) In contrast with L-glycerol 3-phosphate, L-malate or pyruvate, L-glutamine or L-glutamate maintained low rates of oxidative phosphorylation in B-cell mitochondria. The effects of L-glutamine or L-glutamate were potentiated severalfold by (+/-)-BCH. (5) The effects of other branched-chain amino acids on oxidative phosphorylation resembled their effects on insulin release, redox state of nicotinamide nucleotides and glutamate dehydrogenase activity. (6) The results support the view that (+/-)-BCH stimulates insulin secretion via a primary enhancement of hydrogen supply to the respiratory chain of B-cell mitochondria.

Respiration and insulin release in mouse pancreatic islets: Effects of l-leucine and 2-ketoisocaproate in combination with d-glucose and l-glutamine

In order to further evaluate the importance of B-cell metabolism for the stimulation of insulin release, respiration and insulin release were studied in mouse pancreatic islets. Leucine and 2-ketoisocaproate stimulated insulin release during an initial 1-h period, whereas there was no stimulation during two subsequent 1-h periods. This effect was in contrast to that of 16.7 mM glucose, which was a potent stimulator through all the 3 h. Furthermore, the presence of glucose (5.6 mM) or glutamine together with either leucine or 2-ketoisocaproate enhanced the insulin release and prolonged the stimulation. When the kinetics of islet respiration were studied both leucine and 2-ketoisocaproate exerted an initial stimulation on the O 2 uptake which, however, was short-lived (less than 30 min). The presence of 5.6 mM glucose strongly delayed the respiratory retardation seen after the initial stimulation. Similarly, glutamine enhanced the leucine- and 2-ketoisocaproate-stimulated respiratory rates and prevented the respiratory retardation otherwise observed. Leucine (20 mM) and 2-ketoisocaproate (10 and 20 mM) stimulated the oxidation of glucose (5.6 mM). It is concluded that there is a strong correlation between respiratory stimulation and the enhancement of insulin release and that leucine and 2-ketoisocaproate depend on the presence of endogenous fuels for their ability to stimulate islet functions in vitro.

The effect of a day at low irradiance of a maize crop. II. Photosynthesis, transpiration and respiration

The kinetics of daily photosynthesis, transpiration and dark respiration of shoots of maize plants (Zea mays L.) were studied in a growth chamber. After one or two days of reduced light intensity, the photosynthesis and the transpiration returned immediately to a level higher than expected. Respiration, which was reduced by at least 50%, returned slowly for over 2 days towards the initial level. These results suggest the existence of reserves of assimilation products which are used up while maintaining the growth of the aerial part in spite of the lack of assimilation. The prolonged reduction of the respiration shows that it is not strongly correlated to photosyntheis or to growth but rather to the amount of available reserves of assimilate.

Kinetics of oxygen exchange, photosynthesis, and respiration in rivers determined from time-delayed correlations between sunlight and dissolved oxygen

The application of both a simple rate equation and a novel cross-correlation computational technique to dissolved oxygen records has enabled a determination of the oxygen exchange constant, photosynthesis rate, and rate of respiration for several Swiss rivers. An extension of this method to determine total carbonate dynamics from continuous pH records is also described.

Effects of 5-fluorouracil and pantoyl lactone on viability and division of ultraviolet-irradiated Escherichia coli FIL + and FIL - .

Summary: Escherichia colistrains B Hill(FIL+) and B/r(FIL-), when grown on minimal medium containing glycerol, ceased respiration for several hours after ultraviolet (u.v.) irradiation at 520 ergs/mm2. Treatment of cells with 5-fluorouracil (FU) had two effects on viability: (i) pre-irradiation treatment enhanced survival of E. coliB Hill(+) but not that of B/r(FIL-) when survival was measured immediately after irradiation; (ii) pre- or postirradiation treatment of either strain resulted in a large and rapid increase in viability over the first hour of postirradiation incubation. Postirradiation treatment with pantoyl lactone (PL) resulted in a moderate increase in viability, but maintenance of growth and respiration was favoured only by FU. Postirradiation treatment with FU and PL together produced kinetics of respiration, growth and viability intermediate between those observed when the drugs were used separately. Irradiated B Hill organisms, which usually form filaments after u.v. irradiation, only did so in glycerol medium when FU was present. If FU was then replaced by PL, the filaments broke up and viability increased. Viability of B Hill was always higher when irradiated bacteria were plated on agar containing PL than without PL. Thus the increased viability caused by PL and FU when present singly during postirradiation incubation occurred by different means: PL by stimulation of division, and FU by maintenance of respiration.

Studies of Baker's yeast metabolism: III. Oxidation of acetaldehyde

The kinetics of respiration and pyridine nucleotide reduction during acetaldehyde oxidation by baker's yeast have been studied. While a concentration of 0.11 m m acetaldehyde causes a half-maximal saturation of the respiratory system, higher concentrations cause a reversible inhibition of respiration. Titration studies of oxygen with low concentrations (0.5 m m and lower) of acetaldehyde indicate that most of the aldehyde is oxidized, presumably by a DPN-linked dehydrogenase to acetic acid, while the remainder may be reduced to ethanol in short-term experiments. In experiments of longer duration the aldehyde tends to be oxidized completely. The reducing equivalents generated in the oxidation of acetaldehyde to acetic acid are capable of activating oxidative phosphorylation. Acid that is produced by oxidation of acetaldehyde yields hydrogen ions that permeate out of the cell in stoichiometric exchange with extracellular potassium which permeates into the cell.

A note on the kinetics of endogenous respiration of yeast

A note on the kinetics of endogenous respiration of yeast

Considerations of the kinetics of respiration

The kinetics of respiration via carrier chains especially via branched chains are treated. The results can be applied to other reactions of the same type. In the main part of the paper the back reactions are neglected. If there are no carriers in the branches and the back reactions are neglected, the ratios between the reaction rates in the branches depend only on the conditions in the branches. If there is at least one carrier in any branch, the ratios between the rates in the branches depend in addition on the reaction rate, so that a change only in the common chain or of the O 2 pressure alters the ratios between the rates in the branches. The difference in respiration at points at different distances from the periphery of the cell is discussed. The significance of the diffusion constant and the dimensions of the cell is indicated. The influence of the back reactions is only discussed in some simple cases. Even if there are no carriers in the branches the ratio between the rates of oxidation of the substrates depends on the respiration velocity. If the rate in the common chain is below a certain value the reaction in one of the branches becomes a reduction. To show the significance of the ratio between the rates in the branches, a case is treated where the substrates are intermediates in the metabolism of a substance.

Air embolism.

Article1 October 1951AIR EMBOLISMARCHIBALD C. COHEN, GEORGE C. GLINSKY, GEORGE E. MARTIN, F.A.C.P., K. I. FETTERHOFFARCHIBALD C. COHENSearch for more papers by this author, GEORGE C. GLINSKYSearch for more papers by this author, GEORGE E. MARTIN, F.A.C.P.Search for more papers by this author, K. I. FETTERHOFFSearch for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-35-4-779 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptThere are two types of air embolism, differing from each other in the site of entrance of the air, its distribution within the blood vessels, and its effects.1In arterial embolism, the air enters a pulmonary vein, passes through the left ventricle and reaches systemic arteries on the upper part of the body. A small amount of air can block an important artery completely; so the injection of only a few cubic centimeters of air may be fatal if it reaches a cerebral or coronary artery. If air enters the cerebral circulation—this is common if the head is higher than...Bibliography1. DurantLongOppenheimer TMJMJ: Pulmonary (venous) air embolism, Am. Heart J. 33: 269, 1947. CrossrefMedlineGoogle Scholar2. Van AllenHrdina CMLS: Air embolism from the pulmonary vein: a clinical and experimental study, Arch. Surg. 19: 567, 1929. CrossrefGoogle Scholar3. Durant TM: The occurrence of coronary air embolism in artificial pneumothorax, Ann. Int. Med. 8: 1625, 1935. LinkGoogle Scholar4. Pollak M: Air embolus, Am. Rev. Tuberc. 28: 187, 1933. Google Scholar5. Rangell L: Cerebral air embolism, the question of arterialization of intravenous air across the barrier of the pulmonary capillaries: report of a case following assumption of the knee-chest position post partum, with recovery, J. Nerv. and Ment. Dis. 96: 542, 1942. CrossrefGoogle Scholar6. Banyai AL: Personal communication. Google Scholar7. MeneelyWells GREB: Serious air embolism during blood donation, J. A. M. A. 132: 141 (Sept. 21) 1946. CrossrefMedlineGoogle Scholar8 MegibowKatzFeinstein RSLNM: Kinetics of respiration in experimental pulmonary embolism, Arch. Int. Med. 71: 536, 1943. CrossrefGoogle Scholar9. Martland HS: Air embolism, with special reference to its surgical importance, Am. J. Surg. 6: 281, 1945. CrossrefGoogle Scholar10. HeplerTruterHunt TKJLHJ: Air embolism occurring during mastectomy: report of a fatal case, Am. J. Clin. Path. 17: 322, 1947. CrossrefMedlineGoogle Scholar11. Martland HS: Fatal air embolism due to powder insufflations used in gynecological treatments, Am. J. Surg. 68: 164, 1945. CrossrefGoogle Scholar12. HewerCombs CLHI: Fatal air embolism during mastectomy, Brit. M. J. 1: 97, 1948. CrossrefMedlineGoogle Scholar13. Simpson K: Air accidents during transfusion, Lancet 1: 697, 1942. CrossrefGoogle Scholar14. DoyleFrodsham GBP: Fatal air embolism during blood transfusion, Lancet 1: 735, 1949. CrossrefMedlineGoogle Scholar This content is PDF only. To continue reading please click on the PDF icon. Author, Article, and Disclosure InformationAffiliations: *Received for publication March 15, 1950.Reviewed in the Veterans Administration and published with the approval of the Chief Medical Director. The statements and conclusions published by the authors are the result of their own study and do not necessarily reflect the opinion or policy of the Veterans Administration.From the Veterans Administration Hospital, Butler, Pennsylvania, and the City Tuberculosis Hospital, Pittsburgh, Pennsylvania. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited byMassive gas embolism revealed by two consecutive postmortem computed-tomography examinationsPenetrating TraumaAn Unusual Case of Fatal Gas EmbolismGas Embolism: Part I. Venous Gas EmboliAcute Hemiplegia of ChildhoodSurvey of literature related to the problems of gas embolism in human bodyInjuries to the chest caused by pressure changes, compression and decompressionAir Embolism During Pneumoperitoneum TreatmentFatal Air Embolism During Urologic OperationElectrocardiographic manifestations of air in the coronary arteries of dying and resuscitated hearts 1 October 1951Volume 35, Issue 4Page: 779-784KeywordsArteriesBlood vesselsCoronary arteriesLeft ventriclePulmonary arteriesPulmonary embolismVeins ePublished: 1 December 2008 Issue Published: 1 October 1951 PDF downloadLoading ...

The “degree of saturation” in the kinetics of respiration

Journal of Cellular and Comparative PhysiologyVolume 22, Issue 3 p. 273-276 Comments and Communications The “degree of saturation” in the kinetics of respiration O. Klein, O. Klein Wenner-Gren's Institute for exp. Biology, University, Stockholm, SwedenSearch for more papers by this authorJ. Runnström, J. Runnström Wenner-Gren's Institute for exp. Biology, University, Stockholm, SwedenSearch for more papers by this author O. Klein, O. Klein Wenner-Gren's Institute for exp. Biology, University, Stockholm, SwedenSearch for more papers by this authorJ. Runnström, J. Runnström Wenner-Gren's Institute for exp. Biology, University, Stockholm, SwedenSearch for more papers by this author First published: December 1943 https://doi.org/10.1002/jcp.1030220307AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume22, Issue3December 1943Pages 273-276 RelatedInformation

Kinetics of respiration in experimental pulmonary embolism: Megibow, R. S., Katz, L. N., and Feinstein, M.: Arch. Int. Med. 71: 536, 1943

Kinetics of respiration in experimental pulmonary embolism: Megibow, R. S., Katz, L. N., and Feinstein, M.: Arch. Int. Med. 71: 536, 1943

Studies on the kinetics of cell respiration. Oxidation of pyruvic acid by E. Coli, PS. Pyocyaneus, staph. Aureus and saccharomyces cerevisiae

Studies on the kinetics of cell respiration. Oxidation of pyruvic acid by E. Coli, PS. Pyocyaneus, staph. Aureus and saccharomyces cerevisiae

Studies on the kinetics of cell respiration. VII. Respiration of Saccharomyces wanching in acetate, lactate and pyruvate buffer solutions

Studies on the kinetics of cell respiration. VII. Respiration of Saccharomyces wanching in acetate, lactate and pyruvate buffer solutions

Studies on the kinetics of cell respiration. V. Effect of certain organic compounds on the rate of oxygen consumption and of anaerobic CO2 production by Saccharomyces wanching

Studies on the kinetics of cell respiration. V. Effect of certain organic compounds on the rate of oxygen consumption and of anaerobic CO₂ production by Saccharomyces wanching

Studies on the kinetics of cell respiration. VI. Respiration of Chlorella pyrenoidosa in presence of lactates

Studies on the kinetics of cell respiration. VI. Respiration of Chlorella pyrenoidosa in presence of lactates

Studies on the kinetics of cell respiration. IV. Oxidation reduction potentials of Chlorella suspensions in light and in darkness

Studies on the kinetics of cell respiration. IV. Oxidation reduction potentials of Chlorella suspensions in light and in darkness

Studies on the kinetics of cell respiration. II. The effect of ultraviolet light on the rate of oxygen consumption by Saccharomyces Wanching

Studies on the kinetics of cell respiration. II. The effect of ultraviolet light on the rate of oxygen consumption by Saccharomyces Wanching

Studies on the kinetics of cell respiration. II. Parallelism between the rate of oxygen consumption by Saccharomyces Wanching and the change in optical rotation of glucose in boric acid buffers

Studies on the kinetics of cell respiration. II. Parallelism between the rate of oxygen consumption by Saccharomyces Wanching and the change in optical rotation of glucose in boric acid buffers

Studies on the kinetics of cell respiration. I. The rate of oxygen consumption by Saccharomyces wanching as a function of pH

Studies on the kinetics of cell respiration. I. The rate of oxygen consumption by Saccharomyces wanching as a function of pH