The individual effects of CO<sub>2</sub>, bicarbonate and pH on the electrical and mechanical activity of isolated rabbit auricles

Williams, E. M. Vaughan

doi:10.1113/jphysiol.1955.sp005340

Cited by 77 publications

(7 citation statements)

References 61 publications

(52 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…25,26 This effect might have been, however, counterbalanced by a direct cardiovascular depressant effect related to the acidosis with blunting of the catecholamine sensitivity. 27,28 The hypercapnia-induced increase in diastolic arterial pressure observed in the current study could have theoretically resulted in higher coronary perfusion pressure, but this did not translate into a better myocardial function or a decrease in myocardial injury. The slightly lower systemic pH might have increased myocardial oxygen consumption due to increases in left and right ventricle afterload and therefore blunted any hypercapnia-related beneficial effect.…”

Section: Discussionmentioning

confidence: 64%

Effect of mild hypercapnia on outcome and histological injury in a porcine post cardiac arrest model

Babini¹,

Ristagno²,

Boccardo³

et al. 2019

Resuscitation

View full text Add to dashboard Cite

Aim of the study: To evaluate in an established porcine post cardiac arrest model the effect of a mild hypercapnic ventilatory strategy on outcome. Methods: The left anterior descending coronary artery was occluded in 14 pigs and ventricular fibrillation induced and left untreated for 12 min. Cardiopulmonary resuscitation was performed for 5 min prior to defibrillation. After resuscitation, pigs were assigned to either normocapnic (end-tidal carbon dioxide (EtCO 2) target: 35-40 mmHg) or hypercapnic ventilation (EtCO 2 45-50 mmHg). Hemodynamics was invasively measured and EtCO 2 was monitored with an infrared capnometer. Blood gas analysis, serum neuron-specific enolase (NSE) and high sensitive cardiac troponin T (hs-cTnT) were assessed. Survival and functional recovery were evaluated up to 96 h. Results: Twelve pigs were successfully resuscitated and eight survived up to 96 h, with animals in the hypercapnic group showing trend towards a longer survival. EtCO 2 and arterial partial pressure of CO 2 were higher in the hypercapnic group compared to the normocapnic one (p < 0.01), during the 4-hour intervention. Hypercapnia was associated with higher mean arterial pressure compared to normocapnia (p < 0.05). No significant differences were observed in hs-cTnT and in NSE between groups, although the values tended to be lower in the hypercapnic one. Neuronal degeneration was lesser in the frontal cortex of hypercapnic animals compared to the normocapnic ones (p < 0.05). Neurological recovery was equivalent in the two groups.

show abstract

Section: Discussionmentioning

confidence: 64%

Effect of mild hypercapnia on outcome and histological injury in a porcine post cardiac arrest model

Babini¹,

Ristagno²,

Boccardo³

et al. 2019

Resuscitation

View full text Add to dashboard Cite

show abstract

“…A review of the earlier work has been presented by Vaughn Williams (1955), and since that time a substantial degree of effort has been directed at understanding the mechanisms involved.…”

Section: Relationship To Previous Work In Heartmentioning

confidence: 99%

Hydrogen ion modulation of Ca channel current in cardiac ventricular cells. Evidence for multiple mechanisms.

Krafte

Kass

1988

The Journal of General Physiology

View full text Add to dashboard Cite

We have investigated the effects of H ions on (L-type) Ca channel current in isolated ventricular cells. We find that the current amplitude is enhanced in solutions that are alkaline relative to pH 7.4 and reduced in solutions acidic to this pH. We measured pHo-induced shifts in channel gating and analyzed our results in terms of surface potential theory. The shifts are well described by changes in surface potential caused by the binding of H ions to negative charges on the cell surface. The theory predicts a pK of 5.8 for this binding. Gating shifts alone cannot explain all of our observations on modulation of current amplitude. Our results suggest that an additional mechanism contributes to modification of the current amplitude.

show abstract

“…The cardiac depressant effect of lowered pH was later confirmed by Jerusalem, 2 working with cat heart-lung preparations; by Price 3 in dog heart-lung preparations; by "Williams 4 in isolated rabbit auricles; and by McBlroy 5 in isolated guinea-pig hearts.…”

mentioning

confidence: 92%

Influence of Respiratory Acidosis on Circulatory Effect of Epinephrine in Dogs

Bendixen

Laver

Flacke

1963

Circulation Research

View full text Add to dashboard Cite

The circulatory depressant effects of respiratory acidosis and the relation between acidosis and the circulatory effects of epinephrine were studied in anesthetized intact dogs after sympathetic and parasympathetic block. Respiratory acidosis invariably depressed myocardial contractile force, cardiac rate, and mean arterial pressure, but only the fall, in contractile force showed a relation with the degree of acidosis. The effect of epinephrine on myocardial contractile force decreased with decreasing arterial pH, but no correlation was found between pH and the effect of epinephrine on arterial blood pressure and on cardiac rate. During continuous infusion of epinephrine, arterial pressure continued to rise after the contractile force had reached its maximum. With repeated periods of epinephrine infusion in the same animal, the response of the myocardial contractile force declined, while the response of the arterial blood pressure was unchanged. Such "differential tachyphylaxis" may occur under clinical conditions with prolonged infusions of vasopressor agents.

show abstract

The individual effects of CO₂, bicarbonate and pH on the electrical and mechanical activity of isolated rabbit auricles

Cited by 77 publications

References 61 publications

Effect of mild hypercapnia on outcome and histological injury in a porcine post cardiac arrest model

Effect of mild hypercapnia on outcome and histological injury in a porcine post cardiac arrest model

Hydrogen ion modulation of Ca channel current in cardiac ventricular cells. Evidence for multiple mechanisms.

Influence of Respiratory Acidosis on Circulatory Effect of Epinephrine in Dogs

Contact Info

Product

Resources

About

The individual effects of CO2, bicarbonate and pH on the electrical and mechanical activity of isolated rabbit auricles

Cited by 77 publications

References 61 publications

Effect of mild hypercapnia on outcome and histological injury in a porcine post cardiac arrest model

Effect of mild hypercapnia on outcome and histological injury in a porcine post cardiac arrest model

Hydrogen ion modulation of Ca channel current in cardiac ventricular cells. Evidence for multiple mechanisms.

Influence of Respiratory Acidosis on Circulatory Effect of Epinephrine in Dogs

Contact Info

Product

Resources

About

The individual effects of CO₂, bicarbonate and pH on the electrical and mechanical activity of isolated rabbit auricles