Breathing pattern of kittens during hypoxia

Blanco, Carlos E.; Hanson, Mark A.; Johnson, P; Rigatto, Henrique

doi:10.1152/jappl.1984.56.1.12

Cited by 90 publications

(43 citation statements)

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“…The initial increase in ventilation has been attributed to peripheral chemoreceptor activity that was shown not to be depressed during hypoxia in newborn kittens (Blanco, Hanson, Johnson & Rigatto, 1984). The secondary depression, however, was found to be central of origin (Lawson & Long, 1983;Darnall et al 1991).…”

Section: Discussionmentioning

confidence: 99%

The effects of hypoxia on the ventilatory response to sudden changes in CO2 in newborn piglets.

Wolsink

Berkenbosch

DeGoede

et al. 1992

The Journal of Physiology

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SUMMARY1. The ventilatory response to square-wave challenges in end-tidal partial pressure of CO2 (Pc02) was investigated at three levels of arterial Po0 (Pa°2) in nineteen anaesthetized 2-to 11-day-old piglets.2. The ventilatory responses, measured on a breath-to-breath basis, were separated into a peripheral and a central component using a two-compartment model. Both components were described by a CO2 sensitivity, a time constant, a time delay and a single offset.3. Fifty-six responses were analysed against a background ofnormoxaemia (Pa°2 = 12 70 +0O72 kPa, mean + S.D.), fifty-three against a background of moderate hypoxaemia (Pao = 8-63 +034 kPa) and fifty-one against a background of severe hypoxaemia (Pa,02 = 4-98 +030 kPa).4. The sensitivity of the peripheral chemoreceptors in mediating the response to C02 increased from 38-3 + 17-0 ml min-kPa-1 kg-1 during normoxaemia to 48-8 + 15-3 ml min-kPa-1 kg-' during moderate hypoxaemia and to 72-9 + 24-0 ml min-1 kPa-1 kg-1 at severe hypoxaemia.5. As compared with the central CO2 sensitivity during moderate hypoxaemia and normoxaemia (1040± 39-0 and 1008 + 41 6 ml min' kPa-1 kg-', respectively) it decreased to 85 9 + 54-1 ml min-' kPa-1 kg-1 at severe hypoxaemia. 6. We conclude that in newborn piglets there is a positive interaction between hypoxia and hypercapnia at the level of the peripheral chemoreceptors while severe hypoxaemia reduced the C02 sensitivity centrally.

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Section: Discussionmentioning

confidence: 99%

The effects of hypoxia on the ventilatory response to sudden changes in CO2 in newborn piglets.

Wolsink

Berkenbosch

DeGoede

et al. 1992

The Journal of Physiology

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“…Thus, the carotid body of the dunnart may be generally less responsive to hypoxia compared with that of other species. Alternatively, there could be an active, centrally mediated suppression of V E (Blanco et al, 1984;Coles and Dick, 1996).…”

Section: The Journal Of Experimental Biology 215 (24)mentioning

confidence: 99%

The ventilatory response to hypoxia and hypercapnia is absent in the neonatal fat-tailed dunnart

Simpson

Fong

Cummings

et al. 2012

Journal of Experimental Biology

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SUMMARYAt birth, the newborn fat-tailed dunnart relies on cutaneous gas exchange to meet metabolic demands, with continuous lung ventilation emerging several days later. We hypothesised that the delayed expression of lung ventilation (V E ) in these animals is in part due to a low responsiveness of the respiratory control system to blood gas perturbations. To address this hypothesis, we assessed the ventilatory and metabolic response to hypoxia (10% O 2 ) and hypercapnia (5% CO 2 ) using closed-system respirometry from birth to 23days postpartum (P). Neonatal fat-tailed dunnarts displayed no significant hypoxic or hypercapnic ventilatory responses at any age. Regardless, significant hyperventilation through a suppression of metabolic rate (V O2 ) was observed at birth in response to hypercapnia and in response to hypoxia at all ages, except P12. Therefore, reliance on cutaneous gas exchange during early life may be partially attributed to reduced chemosensitivity or a lack of central integration of chemosensitive afferent information. This may be in part due to the relative immaturity of this species at birth, compared with other mammals.

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“…Branched-chain AA may also compete with glutamate for decarboxylation, resulting in increased glutamate levels and consequently reducing the production of GABA, which is a n important respiratory depressant (17)(18)(19). Because a late ventilatory depression occurs in neonates during hypoxia (20)(21)(22)(23) and because this depression may in part be caused by an increase in inhibitory neurotransmitters, counterbalancing their effect by dietary intervention could reverse the ventilatory depression. T o our knowledge, no studies have been conducted to evaluate the influence of AA infusion on the ventilatory response to hypoxia in the neonatal period.…”

mentioning

confidence: 99%

Effect of Amino Acid Infusion on the Ventilatory Response to Hypoxia in Protein-Deprived Neonatal Piglets

et al. 1994

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Divisiorl o f R'c~ot~atolo,~.~~, Dcpurtrnolt ~f Pcdiutrics, Utliver.sitj3 ojl2liut~1i School oj'.\lc~clic.it~c~. ,\liut?~i, FIori(l(1 33101 ABSTRACT. Several amino acids (AA) act a s neurotransmitters and mediate the ventilatory response to carbon dioxide and hypoxia in adult human beings and animals.To evaluate the influence of AA on the neonatal ventilatory response to hypoxia, 29 newborn piglets less than 5 d old were randomly assigned to a control diet or protein-free diet for 7-10 d. Minute ventilation, arterial blood pressure, oxygen consumption, and arterial blood gases were measured in sedated, spontaneous breathing piglets while they breathed room air and at 1, 5 and 10 min of hypoxia p < 0.05). Changes in arterial blood pressure, oxygen consumption, and arterial blood gases during hypoxia were similar before and after AA infusion. The ventilatory response to hypoxia in both protein-free and control diet animals were similar before and after the 10% dextrose infusion. These results stress the importance of nutritional factors in the neonatal control of breathing. (Pediatr Res 35: 316-320, 1994) Abbreviations AA, amino acids D,oW, 10% dextrose ABP, arterial blood pressure BD, base deficit GABA, y-aminobutyric acid VE, minute ventilation Vo2, oxygen consumption VT, tidal volume hypercarbia (1). Furthermore, these respiratory changes were reversed by the administration of enteral or parenteral protein (1-3). In preterm infants, the basal VE and the ventilatory response to hypercarbia were increased after the administration of a standard AA solution (9). The mechanisms that can explain the ventilatory changes during nutritional intervention are not fully defined. Some of these changes may be mediated by the increase and/or decrease in inhibitory or excitatory neurotransmitters in the CNS (4, 10). One of the latter is glutamate, a central excitatory neurotransmitter that participates in the ventilatory response to hypoxia (5). Other AA that are not neurotransmitters may also influence the central respiratory output. For example, the administration of branched-chain AA to adult human beings resulted in an increase in basal ventilation and the ventilatory response to hypercarbia (6, 7). Branched-chain AA may compete with tryptophan at the blood brain bamer, limiting the entry of tryptophan to the CNS and thereby decreasing the production of serotonin. which may be a respiratory inhibitor (1 1-16). Branched-chain AA may also compete with glutamate for decarboxylation, resulting in increased glutamate levels and consequently reducing the production of GABA, which is a n important respiratory depressant (17)(18)(19). Because a late ventilatory depression occurs in neonates during hypoxia (20)(21)(22)(23) and because this depression may in part be caused by an increase in inhibitory neurotransmitters, counterbalancing their effect by dietary intervention could reverse the ventilatory depression. T o our knowledge, no studies have been conducted to evaluate the influence of AA infusion on the ventilatory re...

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Breathing pattern of kittens during hypoxia

Cited by 90 publications

References 0 publications

The effects of hypoxia on the ventilatory response to sudden changes in CO2 in newborn piglets.

The effects of hypoxia on the ventilatory response to sudden changes in CO2 in newborn piglets.

The ventilatory response to hypoxia and hypercapnia is absent in the neonatal fat-tailed dunnart

Effect of Amino Acid Infusion on the Ventilatory Response to Hypoxia in Protein-Deprived Neonatal Piglets

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