TY - JOUR
T1 - Species differences in the chronotropic response to acid-base alterations
AU - Cristina, Maria
AU - de Hurtado, Camilión
AU - Gende, O. A.
AU - Cingolani, H. E.
N1 - Funding Information:
(I) Recipient of a Post doctoral Fellowship from Consejo Nacional de Invesligaciones Cientifcas y TPcnicas (CONICET). (z) Established Investigator, Consejo Nacional de Investigaciones Cientificas y TPcnicas (CONICET). This work was supported in part by a grant from Consejo Nacionalde Investigaciones Cientificas y TPcnicus (CONICET).
PY - 1979
Y1 - 1979
N2 - The chronotropic response to acid-base alterations was studied in isolated spontaneously beating atria of rat, cat and rabbit. In the three species, atrial rate was found to be dependent on extracellular pH. Both "respiratory" and "metabolic" alterations affected chronotropism to the same extent. Decreasing pH from 7.8 led to a decrease in rate in the three species, although the rabbit kept atrial rate constant when pH changed between 7.65 and 7.18. There was a curvilinear relationship between rate and pH so that decreasing pH from 7.8 to 7.4 had a lesser chronotropic effect than decreasing pH below 7.4. However, when atrial rate was plotted against hydrogen ion concentration, an almost linear relationship was obtained. Species differences were observed when assessing the absolute decrease of atrial rate for a given change in pH. The rat was the most responsive of the species tested, while the rabbit possessed the least ability to change its rate in response to modifications in pH.
AB - The chronotropic response to acid-base alterations was studied in isolated spontaneously beating atria of rat, cat and rabbit. In the three species, atrial rate was found to be dependent on extracellular pH. Both "respiratory" and "metabolic" alterations affected chronotropism to the same extent. Decreasing pH from 7.8 led to a decrease in rate in the three species, although the rabbit kept atrial rate constant when pH changed between 7.65 and 7.18. There was a curvilinear relationship between rate and pH so that decreasing pH from 7.8 to 7.4 had a lesser chronotropic effect than decreasing pH below 7.4. However, when atrial rate was plotted against hydrogen ion concentration, an almost linear relationship was obtained. Species differences were observed when assessing the absolute decrease of atrial rate for a given change in pH. The rat was the most responsive of the species tested, while the rabbit possessed the least ability to change its rate in response to modifications in pH.
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U2 - 10.3109/13813457909070523
DO - 10.3109/13813457909070523
M3 - Article
AN - SCOPUS:84907138366
SN - 1381-3455
VL - 87
SP - 593
EP - 602
JO - Archives of Physiology and Biochemistry
JF - Archives of Physiology and Biochemistry
IS - 3
ER -