Effect of breathing upon blood pressure and heart rate in the toad, Bufo arenarum Hensel

1. In unanesthetized toads, Bufo arenarum Hensel, intermittent increases of blood pressure and heart rate were invariably observed when spontaneous breathing increased. When blood pressure reached its maximum the polypnea stopped abruptly and both heart rate and blood pressure declined slowly to the...

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Autores principales: Segura, E.T., Bronstein, A., Schmajuk, N.A.
Formato: JOUR
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_01741578_v143_n2_p223_Segura
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_01741578_v143_n2_p223_Segura2023-10-03T15:07:44Z Effect of breathing upon blood pressure and heart rate in the toad, Bufo arenarum Hensel Segura, E.T. Bronstein, A. Schmajuk, N.A. 1. In unanesthetized toads, Bufo arenarum Hensel, intermittent increases of blood pressure and heart rate were invariably observed when spontaneous breathing increased. When blood pressure reached its maximum the polypnea stopped abruptly and both heart rate and blood pressure declined slowly to their previous values. 2. Sensory stimulation also evoked polypnea followed by hypertension and tachycardia. 3. In the anesthetized animal, artificial lung inflation increased left atrial and mean blood pressure proportionally to the volume of air injected. Similar results were obtained when coelomic instead of lung pressure was increased. In all cases a simultaneous tachycardia was observed. 4. Neither autonomic blockade nor removal of the bulbomesencephalic centres abolished these responses. 5. It is concluded that these pressor and chronotropic effects of breathing are dependent on direct as well as on reflex mechanisms consequent to both coelomic and lung pressure changes. Direct effect of pulmonary venous return (or lower CNS mechanical reflexes) may be important in the intact animal. © 1981 Springer-Verlag. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_01741578_v143_n2_p223_Segura
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description 1. In unanesthetized toads, Bufo arenarum Hensel, intermittent increases of blood pressure and heart rate were invariably observed when spontaneous breathing increased. When blood pressure reached its maximum the polypnea stopped abruptly and both heart rate and blood pressure declined slowly to their previous values. 2. Sensory stimulation also evoked polypnea followed by hypertension and tachycardia. 3. In the anesthetized animal, artificial lung inflation increased left atrial and mean blood pressure proportionally to the volume of air injected. Similar results were obtained when coelomic instead of lung pressure was increased. In all cases a simultaneous tachycardia was observed. 4. Neither autonomic blockade nor removal of the bulbomesencephalic centres abolished these responses. 5. It is concluded that these pressor and chronotropic effects of breathing are dependent on direct as well as on reflex mechanisms consequent to both coelomic and lung pressure changes. Direct effect of pulmonary venous return (or lower CNS mechanical reflexes) may be important in the intact animal. © 1981 Springer-Verlag.
format JOUR
author Segura, E.T.
Bronstein, A.
Schmajuk, N.A.
spellingShingle Segura, E.T.
Bronstein, A.
Schmajuk, N.A.
Effect of breathing upon blood pressure and heart rate in the toad, Bufo arenarum Hensel
author_facet Segura, E.T.
Bronstein, A.
Schmajuk, N.A.
author_sort Segura, E.T.
title Effect of breathing upon blood pressure and heart rate in the toad, Bufo arenarum Hensel
title_short Effect of breathing upon blood pressure and heart rate in the toad, Bufo arenarum Hensel
title_full Effect of breathing upon blood pressure and heart rate in the toad, Bufo arenarum Hensel
title_fullStr Effect of breathing upon blood pressure and heart rate in the toad, Bufo arenarum Hensel
title_full_unstemmed Effect of breathing upon blood pressure and heart rate in the toad, Bufo arenarum Hensel
title_sort effect of breathing upon blood pressure and heart rate in the toad, bufo arenarum hensel
url http://hdl.handle.net/20.500.12110/paper_01741578_v143_n2_p223_Segura
work_keys_str_mv AT seguraet effectofbreathinguponbloodpressureandheartrateinthetoadbufoarenarumhensel
AT bronsteina effectofbreathinguponbloodpressureandheartrateinthetoadbufoarenarumhensel
AT schmajukna effectofbreathinguponbloodpressureandheartrateinthetoadbufoarenarumhensel
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