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Motor nucleus of the V-th nerve and the control of breathing. Breuer-Hering reflexes and apneustic breathing

100%

Gromysz H., Karczewski A. W., Jernajczyk U.

Acta Physiologica Polonica

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1990

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tom 41

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nr 7

Gromysz H., Karczewski W. A., Jernajczyk U.: Motor nucleus of the V-th nerve and the control of breathing. Brener-Hering reflexes and apneustic breathing. Acta Physiol. Pol. Earlier studies from this department have demonstrated that neurones of the V-th nerve motor nucleus (NVmt) have oligosynaptic, inhibitory output to the inspiratory motoneurone themselves under the influence of a polysynaptic input from vagal afferents. To check the hypothesis that NVmt is a part of the pneumotaxic mechanism, we studied the effects of pharmacological microblockade of the NVmt on Breuer-Hering reflexes in halothane-anesthetized, paralyzed and artificially ventilated rabbits. Activities of NVmt neurones and phrenic nerve firing were recorded. Acid-base balance was controlled and histologic examinations were routinely performed. Expiratory activities were regulatory found in NVmt. Its blockade elicited a typical apneustic breathing. During the blockade the Breuer-Hering reflexes gave “paradoxical” effects: an increase in central respiratory frequency following inflation, inspiratory apneusis in response to deflation. We conclude that the NVmt is an important component of the pneumotaxic mechanism or even the anatomical substrate of the pneumotaxic “centre”.

2

Breuer-Hering reflexes in ketamine-induced apneustic breathing in the rabbit

86%

Gromysz H., Karczewski W. A., Kukwa A., Jernajczyk U.

Acta Physiologica Polonica

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1990

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tom 41

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nr 7

Gromysz H., Karczewski W. A., Kukwa A., Jernajczyk U.: Breuer-Hering reflexes in ketamine-induced apneustic breathing in the rabbit. Acta Physiol. Pol. The effects of ketamine on the activities of the mylohyoid nerve (a branch of the Vth nerve) and of both phrenic nerves were investigated in rabbits anaesthetized with halothane, paralyzed and artificially ventilated. Intravenous administration of ketamine elicited a marked prolongation of the phrenic inspiratory discharge [without] not significantly affecting its amplitude) and a depression of the mylohyoid expiratory activity. An elimination of the volume-related input from the lungs (“no inflation manoeuvre” or deflation) elicited under these conditions typical apneustic pattern of breathing. The response to tracheal occlusion at peak-inspiration was “classical”. We conclude that ketamine inhibits the Vth nerve motor nucleus which is not only an important component of the central inspiratory-inhibitory neurones but also a “relay station” between the vagal and the central inspiratory “off-switch” mechanisms.

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Cerebral blood flow in split-brainstem rabbits

86%

Glowicki K., Ryba M., Karczewski W. A.

Acta Physiologica Polonica

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1987

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tom 38

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nr 1

4

Pharmacological impact on loop gain properties to prevent irregular breathing

86%

Kiwull-Schone H., Teppema L., Wiemann M., Kalhoff H., Kiwull P.

Journal of Physiology and Pharmacology

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2008

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tom 59

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nr 1

Theory predicts respiratory instabilities at elevated system loop gain (G), determined by such factors as ventilatory CO2 sensitivity, set-point PCO2, and metabolic rate. In anesthetized rabbits, the effects on G of carbonic anhydrase (CA) inhibitors and of different sodium/proton exchanger type 3 (NHE3) inhibitors were studied. Acetazolamide significantly reduced G by 42.0 ± 9.3% and methazolamide by 35.0 ± 9.5% (each n = 7, P<0.01). Irrespective of the substance, NHE3 inhibition reduced G by 33.0 ± 7.8% (n = 10, P<0.01) at 35.5 ± 1.6 mmHg PaCO2 (mean ±SE), but not at lower arterial CO2 levels (n=5). Since high baseline PCO2 coincides with elevated brainstem NHE3 mRNA expression, this may also account for a higher risk of sleep apnea (or even occurrence of sudden infant death). Therefore, NHE3 inhibitors may gain similar therapeutic importance in the treatment of irregular breathing as CA inhibitors. Generally, effective treatment should aim at a low system loop gain, by reducing respiratory chemosensitivity, improving blood gases and preventing low metabolic rates.

5

Involvement of vagal opioid receptors in respiratory effects of morphine in an anaesthetized rats

86%

Kaczynska K., Szereda-Przestaszewska M.

Journal of Physiology and Pharmacology

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2005

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tom 56

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nr 2

Respiratory effects of morphine injection to the femoral vein were investigated in urethane and chloralose anaesthetized and spontaneously breathing rats, prior to and after midcervical vagotomy. Bolus injection of morphine HCl at a dose of 2 mg/kg of body weight induced depression of ventilation in all rats, due to the significant decrease in tidal volume and to the decline in respiratory rate both pre- and post-vagotomy. Expiratory apnoea of mean duration of 10.0±3.4 s was present in the vagally intact rats only. Bilateral midcervical section of the vagus nerve precluded the occurrence of apnoea. Prolongation of the expiratory time (TE morphine / TE control), which amounted to10.7±2.2-fold in the intact state, was apparently reduced to 1.5±0.3-fold after division of the vagi. Morphine significantly decreased mean arterial pressure (MAP) at 30 s after the challenge, the effect persisted for not less than 1 minute and was absent in vagotomized rats. The respiratory changes evoked by morphine reverted to the control level after intravenous injection of naloxone at a dose of 1 mg/kg. Results of this study indicate that opioid receptors on vagal afferents are responsible for the occurrence of apnoea and hypotension evoked by morphine.

6

Expression of anion exchanger 3 influences respiratory rate in awake and isofurane anesthetized mice

72%

Meier S., Hubner C. A., Groeben H., Peters J., Bingmann D., Wiemann M.

Journal of Physiology and Pharmacology. Supplement

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2007

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tom 58

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nr 5

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Respiratory effects of serotonin challenge to pulmonary and laryngeal circulation in anaesthetized cats

72%

Szereda-Przestaszewska M., Wypych B.

Acta Neurobiologiae Experimentalis

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1996

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tom 56

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nr 4

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Significance of pulmonary vagal afferents for respiratory muscle activity in the cat

58%

Marek W., Muckenhoff K., Prabhakar N. R.

Journal of Physiology and Pharmacology. Supplement

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2008

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tom 59

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nr 6

407-420

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Action of serotonin on the laryngeal airway in anaesthetized cats

58%

Szereda-Przestaszewska M., Kopczynska B.

Acta Neurobiologiae Experimentalis

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1997

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tom 57

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nr 3

Ograniczanie wyników

Motor nucleus of the V-th nerve and the control of breathing. Breuer-Hering reflexes and apneustic breathing

Breuer-Hering reflexes in ketamine-induced apneustic breathing in the rabbit

Cerebral blood flow in split-brainstem rabbits

Pharmacological impact on loop gain properties to prevent irregular breathing

Involvement of vagal opioid receptors in respiratory effects of morphine in an anaesthetized rats

Expression of anion exchanger 3 influences respiratory rate in awake and isofurane anesthetized mice

Respiratory effects of serotonin challenge to pulmonary and laryngeal circulation in anaesthetized cats

Significance of pulmonary vagal afferents for respiratory muscle activity in the cat

Action of serotonin on the laryngeal airway in anaesthetized cats