Respiration physiology最新文献_第2页

Influence of levels of carbon dioxide and oxygen upon gasping in perfused rat preparation. 大鼠灌注制剂中二氧化碳和氧气水平对呼吸的影响。

Respiration physiology Pub Date : 2002-01-01 DOI: 10.1016/S0034-5687(01)00322-X

W. M. St -John, I. Rybak

引用次数: 15

Mechanisms of ventilation inhomogeneity during vital capacity breaths standing and supine 站立和仰卧呼吸时呼吸不均匀的机制

Respiration physiology Pub Date : 2002-01-01 DOI: 10.1016/S0034-5687(01)00318-8

Mikael J Grönkvist , Michael J Emery , Per M Gustafsson

{"title":"Mechanisms of ventilation inhomogeneity during vital capacity breaths standing and supine","authors":"Mikael J Grönkvist , Michael J Emery , Per M Gustafsson","doi":"10.1016/S0034-5687(01)00318-8","DOIUrl":"10.1016/S0034-5687(01)00318-8","url":null,"abstract":"<div>Overall inhomogeneity of ventilation distribution, as measured by single-breath vital capacity (VC) washout (SBW) is known to be greater supine vs. standing. To establish the underlying mechanisms 13 healthy males performed VC SBW of 4% SF6 and He, standing and supine, with or without a 10 sec breathhold (BH). Overall inhomogeneity, as indicated by normalized phase III slopes, was >50% greater supine (SF6 13.1×10−3; He 10.7×10−3 L−1) than standing (SF6 8.6×10−3; He 6.4×10−3 L−1; P<0.001). The (SF6–He) slope, an index of intraacinar inhomogeneity, did not change with posture. Breathholding, assumed to eliminate convective dependent inhomogeneity within and/or between small lung units, produced twice as great reduction of inhomogeneity when supine vs. standing. After BH inhomogeneity remained significantly greater supine vs. standing. In conclusion, at least two events seem to underlie the increased inhomogeneity when supine: (1) a substantially increased convection dependent non-uniformity between well-separated lung regions; and (2) a somewhat increased convection dependent non-uniformity within and/or between peripherally located lung units.</div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00318-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86787920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Type I nitric oxide synthase in the human lung is predominantly expressed in capillary endothelial cells 人肺I型一氧化氮合酶主要在毛细血管内皮细胞中表达

Respiration physiology Pub Date : 2002-01-01 DOI: 10.1016/S0034-5687(01)00323-1

Hardi Lührs , Thomas Papadopoulos , Harald H.H.W Schmidt , Thomas Menzel

引用次数: 37

Eicosanoids modulate hyperpnea-induced late phase airway obstruction and hyperreactivity in dogs 类二十烷醇调节高呼吸诱导的晚期气道阻塞和狗的高反应性

Respiration physiology Pub Date : 2002-01-01 DOI: 10.1016/S0034-5687(01)00317-6

Michael S Davis, Sharron McCulloch, Teresa Myers, Arthur N Freed

{"title":"Eicosanoids modulate hyperpnea-induced late phase airway obstruction and hyperreactivity in dogs","authors":"Michael S Davis, Sharron McCulloch, Teresa Myers, Arthur N Freed","doi":"10.1016/S0034-5687(01)00317-6","DOIUrl":"10.1016/S0034-5687(01)00317-6","url":null,"abstract":"<div>A canine model of exercise-induced asthma was used to test the hypothesis that the development of a late phase response to hyperventilation depends on the acute production of pro-inflammatory mediators. Peripheral airway resistance, reactivity to hypocapnia and aerosol histamine, and bronchoalveolar lavage fluid (BALF) cell and eicosanoid content were measured in dogs ∼5 h after dry air challenge (DAC). DAC resulted in late phase obstruction, hyperreactivity to histamine, and neutrophilic inflammation. Both cyclooxygenase and lipoxygenase inhibitors administered in separate experiments attenuated the late phase airway obstruction and hyperreactivity to histamine. Neither drug affected the late phase inflammation nor the concentrations of eicosanoids in the BALF obtained 5 h after DAC. This study confirms that hyperventilation of peripheral airways with unconditioned air causes late phase neutrophilia, airway obstruction, and hyperreactivity. The late phase changes in airway mechanics are related to the hyperventilation-induced release of both prostaglandins and leukotrienes, and appear to be independent of the late phase infiltration of inflammatory cells.</div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00317-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77664350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Effects of neural drives on breathing in the awake state in humans 人类清醒状态下神经驱动对呼吸的影响

Respiration physiology Pub Date : 2002-01-01 DOI: 10.1016/S0034-5687(01)00325-5

Guy Longobardo, Carlo J Evangelisti, Neil S Cherniack

{"title":"Effects of neural drives on breathing in the awake state in humans","authors":"Guy Longobardo, Carlo J Evangelisti, Neil S Cherniack","doi":"10.1016/S0034-5687(01)00325-5","DOIUrl":"10.1016/S0034-5687(01)00325-5","url":null,"abstract":"<div>We have developed a mathematical model of the regulation of ventilation that successfully simulates breathing in the awake as well as in sleeping states. In previous models, which were used to simulate Cheyne–Stokes breathing and respiration during sleep, the controller was only responsive to chemical stimuli, and allowed no ventilation at sub-normal carbon dioxide levels. The current model includes several new features. The chemical controller responds continuously to changes in PCO2 with a lower sensitivity during hypocapnia than in the hypercapnic ranges. Hypoxia interacts multiplicatively with PCO2 over the entire range of activity. The controller in the current model, besides the chemical drive, includes also a neural component. This neural drive increases and decreases as the level of alertness changes, and adds or subtracts from ventilation levels demanded by the chemical controller. The model also includes the effects of post-stimulus potentiation (PSP) and hypoxic ventilatory depression (HVD). While PSP eliminates apneas after a disturbance and also dampens the subsequent dynamics of the respiration, it is not a major factor in the damping of the response. Another finding is that HVD is destabilizing. The model is the first to reproduce results reported in conscious humans after hyperventilation and after acute and longer-term hypoxia. It also reproduces the effects of NREM sleep.</div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00325-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84932334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 42

Influence of levels of carbon dioxide and oxygen upon gasping in perfused rat preparation 大鼠灌注制剂中二氧化碳和氧气水平对呼吸的影响

Respiration physiology Pub Date : 2002-01-01 DOI: 10.1016/S0034-5687(01)00322-X

Walter M St.-John , Ilya A Rybak

{"title":"Influence of levels of carbon dioxide and oxygen upon gasping in perfused rat preparation","authors":"Walter M St.-John , Ilya A Rybak","doi":"10.1016/S0034-5687(01)00322-X","DOIUrl":"https://doi.org/10.1016/S0034-5687(01)00322-X","url":null,"abstract":"<div>In vivo, the augmenting pattern of integrated phrenic nerve discharge of eupnea is altered to the decrementing pattern of gasping in severe hypoxia or ischaemia. Identical alterations in phrenic discharge are found in perfused in situ preparations of the juvenile rat. In this preparation, gasping was produced by equilibration of the perfusate with various levels of carbon dioxide and oxygen. The duration of the phrenic burst, the interval between bursts and the burst amplitude were not significantly different following equilibration with 21–6%O2 at 5% CO2 or with 0–9% CO2 at 6% O2, with the exception that the burst amplitude was significantly greater in hypercapnic-hypoxia (9% CO2 at 6% O2). It is proposed that hypoxia-induced gasping results from the release of an endogenous pacemaker activity of rostral medullary neurons. This release is caused by cellular mechanisms that change the balance between membrane ionic currents. Moreover, these cellular mechanisms may be explicitly induced by alterations in the ionic and metabolic homeostasis.</div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00322-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89999162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

Olfactory CO2 chemoreceptors 嗅觉二氧化碳化学感受器

Respiration physiology Pub Date : 2001-12-01 DOI: 10.1016/S0034-5687(01)00292-4

E.Lee Coates

{"title":"Olfactory CO2 chemoreceptors","authors":"E.Lee Coates","doi":"10.1016/S0034-5687(01)00292-4","DOIUrl":"10.1016/S0034-5687(01)00292-4","url":null,"abstract":"<div>Amphibians and reptiles possess CO2-sensitive olfactory receptors that cause a dose-dependent decrease in breathing when stimulated by CO2 concentrations ranging from 0.5 to 8%. In amphibians, it has been shown that inhibition of the enzyme, carbonic anhydrase (CA), attenuates the response of CO2-sensitive olfactory receptors to transient changes in nasal CO2. Histology and electrophysiology studies in frogs show that identification of sites of CA activity can serve as markers for locations of CO2 chemosensitivity in the olfactory epithelium. There is also growing evidence that CO2 receptors may be present in the olfactory epithelium of mammals. The objectives of this review are to, (1) summarize the current state of knowledge of olfactory CO2 receptors in amphibians, reptiles, and mammals; (2) present results from an experiment designed to determine the distribution and density of CA activity within the rat nasal cavity; (3) show results from an experiment that recorded the olfactory receptor response to CO2 in areas of the rat nasal cavity exhibiting the highest densities of CA activity; and (4) discuss the presumed role of the olfactory CO2 receptors in the control of breathing and in abnormalities of breathing, such as sudden infant death syndrome (SIDS).</div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00292-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75961525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 55

Respiratory plasticity: differential actions of continuous and episodic hypoxia and hypercapnia 呼吸可塑性:连续性和偶发性缺氧和高碳酸血症的不同作用

Respiration physiology Pub Date : 2001-12-01 DOI: 10.1016/S0034-5687(01)00280-8

T.L Baker , D.D Fuller , A.G Zabka , G.S Mitchell

{"title":"Respiratory plasticity: differential actions of continuous and episodic hypoxia and hypercapnia","authors":"T.L Baker , D.D Fuller , A.G Zabka , G.S Mitchell","doi":"10.1016/S0034-5687(01)00280-8","DOIUrl":"10.1016/S0034-5687(01)00280-8","url":null,"abstract":"<div>The objectives of this paper are: (1) to review advances in our understanding of the mechanisms of respiratory plasticity elicited by episodic versus continuous hypoxia in short to intermediate time domains (min to h); and (2) to present new data suggesting that different patterns of hypercapnia also elicit distinct forms of respiratory plasticity. Episodic, but not continuous hypoxia elicits long-term facilitation (LTF) of respiratory motor output. Phrenic LTF is a serotonin-dependent central neural mechanism that requires: (a) activation of spinal serotonin receptors; and (b) spinal protein synthesis. Continuous and episodic hypercapnia also elicit different mechanisms of plasticity. Continuous, severe hypercapnia (25 min of ∼10% inspired CO2) elicits long-term depression (LTD) of phrenic motor output (−33±8% at 60 min post-hypercapnia) in anesthetized rats. In contrast, 3,5 min hypercapnic episodes do not elicit LTD (9±17% at 60 min). We hypothesize that the response of respiratory motoneurons to serotonergic and noradrenergic modulation may contribute to pattern sensitivity to hypoxia and hypercapnia.</div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00280-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91271759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 102

Central Chemosensitivity 中央化学敏感性

Respiration physiology Pub Date : 2001-12-01 DOI: 10.1016/S0034-5687(01)00298-5

David J Ballantyne, Jay B Dean, Robert W Putnam

引用次数: 0

Localization of connexin26 and connexin32 in putative CO2-chemosensitive brainstem regions in rat 大鼠二氧化碳化学敏感脑干区连接蛋白26和连接蛋白32的定位

Respiration physiology Pub Date : 2001-12-01 DOI: 10.1016/S0034-5687(01)00299-7

Irene C. Solomon, Tami J. Halat, M.Raafat El-Maghrabi, Marvin H. O'Neal III

{"title":"Localization of connexin26 and connexin32 in putative CO2-chemosensitive brainstem regions in rat","authors":"Irene C. Solomon, Tami J. Halat, M.Raafat El-Maghrabi, Marvin H. O'Neal III","doi":"10.1016/S0034-5687(01)00299-7","DOIUrl":"10.1016/S0034-5687(01)00299-7","url":null,"abstract":"<div>Recent studies have suggested that cell-to-cell coupling, which occurs via gap junctions, may play a role in CO2 chemoreception. Here, we used immunoblot and immunohistochemical analyses to investigate the presence, distribution, and cellular localization of the gap junction proteins connexin26 (Cx26) and connexin32 (Cx32) in putative CO2-chemosensitive brainstem regions in both neonatal and adult rats. Immunoblot analyses revealed that both Cx subtypes were expressed in putative CO2-chemosensitive brainstem regions; however, regional differences in expression were observed. Immunohistochemical experiments confirmed Cx expression in each of the putative CO2-chemosensitive brainstem regions, and further demonstrated that Cx26 and Cx32 were found in neurons and Cx26 was also found in astrocytes in these regions. Thus, our findings suggest the potential for gap junctional communication in these regions in both neonatal and adult rats. We propose that the gap junction proteins Cx26 and Cx32, at least in part, form the neuroanatomical substrate for this gap junctional communication, which is hypothesized to play a role in central CO2 chemoreception.</div>","PeriodicalId":20976,"journal":{"name":"Respiration physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0034-5687(01)00299-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81619500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 54