Pulmonary mechanics during hypoxia in spontaneously breathing anesthetized rabbits

Delpierre, S.; Fornaris, E.; Fornaris, M; Grimaud, C

doi:10.1016/0165-1838(80)90036-3

Cited by 4 publications

(2 citation statements)

References 26 publications

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“…We have observed that par alyzed, mechanically ventilated rabbits may exhibit mild hypoxemia (PaO,: 50-65 Torr). To avoid the possibility of vagally mediated reflex bronchocon striction induced by hypoxemia [16,17], supplemen tal oxygen was provided at 2 liters/min. These venti lator settings resulted in a PaO; in excess of 200 Torr and a PaC02 between 35 and 45 Torr.…”

Section: Methodsmentioning

confidence: 99%

Variability of Pulmonary Responsiveness to Aerosolized Histamine in Normal Rabbits

Quan¹,

Witten

Stevenson

et al. 1986

Respiration

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Considerable between-subject variability in pulmonary responsiveness to histamine has been reported in normal human subjects, dogs, guinea pigs, and rhesus monkeys, but rabbits have not been studied. We determined the between- and within-rabbit variability of pulmonary histamine responsiveness in 34 anesthetized and mechanically ventilated New Zealand White rabbits. In 30 rabbits, 5 breaths of aerosolized histamine were delivered in 9 increasing concentrations ranging from 0.01 to 100 mg/ ml. Eleven of 30 rabbits were rechallenged with histamine on 1–4 additional occasions over a 3-week period. In the remaining 4 rabbits, 9 doses of distilled H₂O were aerosolized to determine the degree of spontaneous variability in measurements of lung resistance (Rl) and dynamic lung compliance (C_dyn)· We defined an increase in Rl of greater than 50% of baseline (TD₅₀R_L and a decrease in C_dyn of greater than 25% of baseline (TD₂₅C_dyn) as being significant based on observations in these 4 rabbits. These limits exceeded the 99.9 percentile of spontaneous variability in R_l and Cd_yn· Pulmonary responsiveness to histamine varied widely, with a greater than 10,000-fold range in TD₅₀R_L and a 1,000-fold range in TD₂₅C_dyn between the most and least sensitive rabbits. The variability of this responsiveness was log-normally distributed. It was not correlated with age, sex, or baseline Rl and C_dyn· In contrast, within-rabbit responses to histamine challenge were quite reproducible. Five of 30 rabbits were killed at the conclusion of their histamine challenges for pathologic examination of their lungs. No evidence of airway inflammation was found. We conclude that pulmonary histamine responsiveness in normal rabbits is qualitatively similar to that previously observed in guinea pigs and mongrel dogs, and may be an important factor in assessing airway reactivity in rabbit models of asthma

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Section: Methodsmentioning

confidence: 99%

Variability of Pulmonary Responsiveness to Aerosolized Histamine in Normal Rabbits

Quan¹,

Witten

Stevenson

et al. 1986

Respiration

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“…These contradictory results may have been obtained because of the considerable variability among different species and because different experimental preparations were used. Most of the animal studies on hypoxia have been done under closed-chest, nonvagotomized conditions (4,5,10,23,24). However, Hantos et al (11) reported that chest wall resistance makes up a substantial component of RL in the rat.…”

mentioning

confidence: 99%

Acute response of the lung mechanics of the rabbit to hypoxia

Sakai¹,

Fukui

Nakano³

et al. 1999

Journal of Applied Physiology

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We measured the change in total lung resistance (RL) and that in total lung elastance (EL) induced by hypoxia (n = 7) and compared the results with those by intravenous histamine bolus (n = 5) at three different positive end-expiratory pressure (PEEP) levels (2, 5, and 8 hPa) in open-chest and vagotomized rabbits. The percent increase ratio of RL (PIRR) and EL (PIRE) was defined as the change in RL and EL, respectively, induced by hypoxia compared with that in the normoxic condition, expressed as a percentage. PIR values for the change in RL and EL induced by bolus injection of histamine were also calculated. The PIRR and PIRE induced by hypoxia and by histamine were positive by a statistically significant amount at every PEEP level, except for the PIRE value at 8-hPa PEEP in the hypoxic challenge. The PIRE-to-PIRR ratio values in the hypoxic challenge at 2-hPa PEEP were significantly larger than those in the histamine challenge (hypoxia: 0.91 +/- 0.23%; histamine: 0.37 +/- 0. 065%, P < 0.05). The increase in EL induced by histamine in the acute phase has been reported to be mainly derived from tissue distortion secondary to bronchial constriction. Thus our results suggest that a part of the increase in EL by hypoxia was originated in different parenchymal responses from histamine and imply that this hypoxic response of lung parenchyma is sensitive to the increase in parenchymal tethering at high PEEP levels.

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Distribution of pulmonary cholinergic nerves in the rabbit.

El-Bermani¹,

Bloomquist²,

Montvilo³

1982

Thorax

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Investigations of the nerves of the rabbit lung, by light and electron microscopy, showed a dense acetylcholinesterase-positive innervation of the bronchi through the bronchiolar level. Large nerve bundles were found to decrease in size as they progressed from extrachondral to subchondral connective tissue, forming complex networks of mostly terminal fibres in the muscle layer. In several instances single fibres penetrated the submucosal layer and approached the mucosa. Gangliocytes, which also reacted positively for cholinesterase, were visible in the vicinity of the large peribronchial bundles. Gangliocytes rarely were seen in association with the vasculature. Blood vessels received a much less dense cholinesterase-positive nerve supply than the bronchi. Single, non-terminal fibres were noted at the adventitiomedial junction of the pulmonary artery and vein. In addition, segments of nerve fibres (networks) were observed in the arterial and venous smooth muscle layers. Cholinesterase-positive innervation was even less extensive in the veins than in the arteries. Methods LIGHT MICROSCOPYAlbino rabbits, weighing an average of 3 kg, were injected intraperitoneally with sodium pentobarbitol. The lungs, judged to be free of disease on macroscopic examination, were placed on aluminium foil and frozen on dry ice (-70°C).Serial frozen sections of 20-30 ,m were collected on coverslips, air-dried for a few minutes, and fixed in 4% neutral formol-saline solution for 15 minutes. The sections were incubated at 37°C for 90 minutes, according to the procedure of Karnovsky and Roots'6 as modified by El-Badawi and Schenk."7The substrate for the specific cholinesterase reaction was acetylthiocholine iodide; tetraisopropylpyrophosphoramide (iso-OMPA) at a concentration of 80 mmolI was used to inhibit non-specific cholinesterase. ELECTRON MICROSCOPYA modification of the procedure described by Kokko et al'8 was used to demonstrate acetylcholinesterase for electron microscopy. After a saline washout of the pulmonary circulation the left lung was perfused with a solution of 3% formaldehyde and 1% glutaraldehyde in Sorensen's phosphate buffer (pH 7.0) through the pulmonary artery 703 on 27 April 2019 by guest. Protected by copyright.

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Pulmonary mechanics during hypoxia in spontaneously breathing anesthetized rabbits

Cited by 4 publications

References 26 publications

Variability of Pulmonary Responsiveness to Aerosolized Histamine in Normal Rabbits

Variability of Pulmonary Responsiveness to Aerosolized Histamine in Normal Rabbits

Acute response of the lung mechanics of the rabbit to hypoxia

Distribution of pulmonary cholinergic nerves in the rabbit.

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