Influence of acid-base alterations on myocardial sensitivity to catecholamines
The influence of “respiratory” and “metabolic” acid-base alterations on the myocardial sensitivity to catecholamines was studied in the isolated rat atria. The ability of noradrenaline for increasing the atrial rate was enhanced during alkalosis and conversely, it was decreased by acidosis. These ch...
| Autores principales: | , , |
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| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
1981
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/131072 |
| Aporte de: |
| id |
I19-R120-10915-131072 |
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| record_format |
dspace |
| institution |
Universidad Nacional de La Plata |
| institution_str |
I-19 |
| repository_str |
R-120 |
| collection |
SEDICI (UNLP) |
| language |
Inglés |
| topic |
Ciencias Médicas Salud Acid-base alterations Cyclic AMP Atrial rate Catecholamines |
| spellingShingle |
Ciencias Médicas Salud Acid-base alterations Cyclic AMP Atrial rate Catecholamines Camilión de Hurtado, María Cristina Argel, María Isabel Cingolani, Horacio Eugenio Influence of acid-base alterations on myocardial sensitivity to catecholamines |
| topic_facet |
Ciencias Médicas Salud Acid-base alterations Cyclic AMP Atrial rate Catecholamines |
| description |
The influence of “respiratory” and “metabolic” acid-base alterations on the myocardial sensitivity to catecholamines was studied in the isolated rat atria. The ability of noradrenaline for increasing the atrial rate was enhanced during alkalosis and conversely, it was decreased by acidosis. These changes in sensitivity shifted the concentration-effect curve for noradrenaline to the right by about 0.5 log unit when the pH was lowered from 7.60 to 7.00. No changes in the maximum attainable response were detected. Essentially the same shifts of the concentration-effect curves were obtained with changes in pH brought about by altering the pCO2 or at constant pCO2. The decrease in the pH produced a similar shift to the right of the concentration-effect curve for isoprenaline, after the extraneuronal uptake inhibition by hydrocortisone and also in atria tissue with low content of endogenous noradrenaline (reserpine-pretreated and newborn rats). The ability of isoprenaline for increasing cyclic AMP levels in atrial tissue was also enhanced by alkalosis and decreased by acidosis. However, the shift to the right of the concentration-effect curve for cyclic AMP induced by the decrease in the pH was greater than the shift detected in the chronotropic-effect curve. In addition a decrease in the maximum increment of cyclic AMP was detected under acidosis, in spite of equal maximal chronotropic response.
Our results support the hypothesis that the alterations in the sensitivity to catecholamines induced by the changes in pH are not due to a release of endogenous noradrenaline nor to alterations of the mechanisms which remove catecholamines from the biophase. The fact that cyclic AMP response to catecholamines was also reduced by acidosis strongly suggests that the mechanism(s) involved is located in the earlier steps of the events leading to the chronotropic effect of the β-agonists. |
| format |
Articulo Articulo |
| author |
Camilión de Hurtado, María Cristina Argel, María Isabel Cingolani, Horacio Eugenio |
| author_facet |
Camilión de Hurtado, María Cristina Argel, María Isabel Cingolani, Horacio Eugenio |
| author_sort |
Camilión de Hurtado, María Cristina |
| title |
Influence of acid-base alterations on myocardial sensitivity to catecholamines |
| title_short |
Influence of acid-base alterations on myocardial sensitivity to catecholamines |
| title_full |
Influence of acid-base alterations on myocardial sensitivity to catecholamines |
| title_fullStr |
Influence of acid-base alterations on myocardial sensitivity to catecholamines |
| title_full_unstemmed |
Influence of acid-base alterations on myocardial sensitivity to catecholamines |
| title_sort |
influence of acid-base alterations on myocardial sensitivity to catecholamines |
| publishDate |
1981 |
| url |
http://sedici.unlp.edu.ar/handle/10915/131072 |
| work_keys_str_mv |
AT camiliondehurtadomariacristina influenceofacidbasealterationsonmyocardialsensitivitytocatecholamines AT argelmariaisabel influenceofacidbasealterationsonmyocardialsensitivitytocatecholamines AT cingolanihoracioeugenio influenceofacidbasealterationsonmyocardialsensitivitytocatecholamines |
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Repositorios |
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