Chemoreceptor stimulation and hypoxic pulmonary vasoconstriction in conscious dogs

Levitzky, Michael G.

doi:10.1016/0034-5687(79)90067-7

Cited by 41 publications

(36 citation statements)

References 16 publications

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“…This possibility is reinforced again in Figure 8B by the facts that (1) HHint does not differ from HHabr and (2) COHint is larger than HHint and HHabr, but does not differ from COHabr. The apparent vasodilatory action of the cbs on the vasculature of the adrenals and eyes is consistent with the action of the cbs on the pulmonary vasculature during hypoxic pulmonary vasoconstriction (Fitzgerald, et al, 2012; Fitzgerald, et al, 1992; Levitzky, 1979; Levitzky, et al, 1977; Wilson, and Levitzky,1989). To our knowledge no other study of the effects of hypoxemia on feline vasculature report the effects of hypoxemia on the ocular bed.…”

Section: Discussionsupporting

confidence: 71%

Autonomic regulation of organ vascular resistances during hypoxemia in the cat

Fitzgerald

Dehghani

Kiihl

2013

Autonomic Neuroscience

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This study aimed to dissect the roles played by the autonomic interoreceptors, the carotid bodies (cbs) and the aortic bodies (abs) on the vascular resistances of several organs in anesthetized, paralyzed, artificially ventilated cats challenged by systemic hypoxemia. Two 15 min challenges stimulated each of 5 animals in two different groups: (1) In the intact group hypoxic hypoxia (10%O2 in N2; HH) stimulated both abs and cbs, increasing neural output to the nucleus tractus solitarius (NTS); (2) In this group carbon monoxide hypoxia (30%O2 in N2 with the addition of CO; COH) stimulated only the abs, increasing neural output to the NTS. (3) In the second group in which their bilateral aortic depressor nerves had been transected only the cbs increased neural output to the NTS during the HH challenge; (4) In this aortic body resected group during COH neither abs nor cbs increased neural traffic to the NTS. CO and 10%O2 reduced Hb saturation to the same level. With the use of radiolabeled microspheres blood flow was measured in a variety of organs. Organ vascular resistance was calculated by dividing the aortic pressure by that organ’s blood flow. The spleen and pancreas revealed a vasoconstriction in the face of systemic hypoxemia, thought to be sympathetic nervous system(SNS)-mediated. The adrenals and the eyes vasodilated only when cbs were stimulated. Vasodilation in the heart and diaphragm showed no effect of chemoreceptor stimulated increase in SNS output. Different chemoreceptor involvement had different effects on the organs.

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Section: Discussionsupporting

confidence: 71%

Autonomic regulation of organ vascular resistances during hypoxemia in the cat

Fitzgerald

Dehghani

Kiihl

2013

Autonomic Neuroscience

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“…Animal studies have clearly demonstrated that higher peripheral chemoreceptor responsiveness attenuates HPV 10,11 . For example, following mechanical ventilation of the lungs with 100% N 2 , stimulation of the carotid chemoreceptors via arterial hypoxemia reduces pulmonary vascular resistance in cats and dogs 12,13 .…”

Section: Introductionmentioning

confidence: 99%

Chemoreceptor Responsiveness at Sea Level Does Not Predict the Pulmonary Pressure Response to High Altitude

Hoiland

Foster

Donnelly

et al. 2015

Chest

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Abstract:The hypoxic ventilatory response (HVR) at sea level (SL) is moderately predictive of the change in pulmonary artery systolic pressure (PASP) to acute normobaric hypoxia. However, because of progressive changes in the chemoreflex control of breathing and acid-base balance at high altitude (HA), HVR at SL may not predict PASP at HA. We hypothesized that resting peripheral oxyhemoglobin saturation (SpO 2 ) at HA would correlate better than HVR at SL to PASP at HA. In 20 participants at SL, we measured normobaric, isocapnic HVR (L/min·-%SpO 2 -1 ) and resting PASP using echocardiography.Both resting SpO 2 and PASP measures were repeated on day 2 (n=10), days 4-8 (n=12), and 2-3 weeks (n=8) after arrival at 5050m. These data were also collected at 5050m on life-long HA residents (Sherpa; n=21

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“…Another difference between the unilateral hypoxic and hypoxemic conditions relates to the pulmonary circulation. During unilateral hypoxia there is pulmonary vasoconstriction and shunting of pulmonary blood flow to the nonhypoxic lung, but pulmonary arterial pressures do not increase very much because of the reserve capacity of the contralateral pulmonary circulation (11). With hypoxemia, however, the entire pulmonary bed constricts, but because cardiac output is maintained, pulmonary arterial pressure increases dramatically (15).…”

mentioning

confidence: 99%

Effect of hypoxia on respiratory system impedance in dogs

Simon

Zanaboni

Nyhan

1997

Journal of Applied Physiology

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The effects of hypoxia on lung and airway mechanics remain controversial, possibly because of the confounding effects of competing reflexes caused by systemic hypoxemia. We compared the effects of systemic hypoxemia with those of unilateral alveolar hypoxia (with systemic normoxemia) on unilateral respiratory system impedance (Z) in intact, anesthetized dogs. Independent lung ventilation was obtained with a Kottmeier endobronchial tube. Individual left and right respiratory system Z was measured during sinusoidal forcing with 45 ml of volume at frequencies of 0.2-2.1 Hz during control [100% inspired O2 fraction (FIO2)], systemic hypoxemia (10% FIO2), and unilateral alveolar hypoxia (0% FIO2 to left lung, 100% FIO2 to right lung). During systemic hypoxemia, there was a mean Z magnitude increase of 18%. This change was entirely attributable to a decrease in the imaginary component of Z; there was no change in the real component of Z. Administration of atropine (0.2 mg/kg) did not block the increase in Z with systemic hypoxemia. In contrast, there was no change in Z in the lung subjected to unilateral alveolar hypoxia. We conclude that alveolar hypoxia has no direct effect on lung mechanical properties in intact dogs. In contrast, systemic hypoxemia does increase lung impedance, apparently through a noncholinergic mechanism.

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Chemoreceptor stimulation and hypoxic pulmonary vasoconstriction in conscious dogs

Cited by 41 publications

References 16 publications

Autonomic regulation of organ vascular resistances during hypoxemia in the cat

Autonomic regulation of organ vascular resistances during hypoxemia in the cat

Chemoreceptor Responsiveness at Sea Level Does Not Predict the Pulmonary Pressure Response to High Altitude

Effect of hypoxia on respiratory system impedance in dogs

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