TY - JOUR
T1 - Reflex cardiovascular and respiratory effects of serotonin in conscious and anesthetized dogs
AU - Zucker, I. H.
AU - Cornish, K. G.
PY - 1980
Y1 - 1980
N2 - Cardiovascular and respiratory effects of intra-left atrial or intra-left ventricular injection of serotonin were studied in conscious dogs (n = 8), anesthetized closed-chest dogs (n = 13) and anesthetized open-chest dogs (n = 9). Serotonin (50-200 μg), injected as a bolus, resulted in an initial bradycardia and hypotension followed by a delayed tachycardia and hypertension in the conscious dogs. The hypertension was seen as an increase of 21.5 ± 2.7 (mean ± SE) mm Hg from a control pressure of 102.5 ± 1.9 mm Hg, whereas the initial decrease in pressure was 22.6 ± 1.9 mm Hg. The tachycardia was 23.3 ± 3.9 beats/min above a control heart rate of 104.9 ± 3.9 beats/min whereas the bradycardia was 58.5 ± 3.7 beats/min below control. There was a significant attenuation of the hypotension in both groups of anesthetized dogs. In fact, no hypotension was elicited in the open-chest anesthetized dogs. Open-chest anesthetized dogs showed only a hypertensive response (mean increase 67.2 ± 5.5 mm Hg). Stimulation of respiration was seen in all groups of dogs. In conscious dogs there was a 214.8 ± 15.4% increase in respiratory depth and a 20.8 ± 3.1 breaths/min increase in respiratory rate. Atropine significantly reduced the bradycardia and abolished the hypotension in conscious dogs. Bilateral cervical vagotomy did not abolish the response in open-chest anesthetized dogs. We conclude that the so-called 'hypertensive coronary chemoreflex' is altered dramatically by the state of the preparation and by anesthesia.
AB - Cardiovascular and respiratory effects of intra-left atrial or intra-left ventricular injection of serotonin were studied in conscious dogs (n = 8), anesthetized closed-chest dogs (n = 13) and anesthetized open-chest dogs (n = 9). Serotonin (50-200 μg), injected as a bolus, resulted in an initial bradycardia and hypotension followed by a delayed tachycardia and hypertension in the conscious dogs. The hypertension was seen as an increase of 21.5 ± 2.7 (mean ± SE) mm Hg from a control pressure of 102.5 ± 1.9 mm Hg, whereas the initial decrease in pressure was 22.6 ± 1.9 mm Hg. The tachycardia was 23.3 ± 3.9 beats/min above a control heart rate of 104.9 ± 3.9 beats/min whereas the bradycardia was 58.5 ± 3.7 beats/min below control. There was a significant attenuation of the hypotension in both groups of anesthetized dogs. In fact, no hypotension was elicited in the open-chest anesthetized dogs. Open-chest anesthetized dogs showed only a hypertensive response (mean increase 67.2 ± 5.5 mm Hg). Stimulation of respiration was seen in all groups of dogs. In conscious dogs there was a 214.8 ± 15.4% increase in respiratory depth and a 20.8 ± 3.1 breaths/min increase in respiratory rate. Atropine significantly reduced the bradycardia and abolished the hypotension in conscious dogs. Bilateral cervical vagotomy did not abolish the response in open-chest anesthetized dogs. We conclude that the so-called 'hypertensive coronary chemoreflex' is altered dramatically by the state of the preparation and by anesthesia.
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U2 - 10.1161/01.RES.47.4.509
DO - 10.1161/01.RES.47.4.509
M3 - Article
C2 - 7408129
AN - SCOPUS:0018964861
SN - 0009-7330
VL - 47
SP - 509
EP - 515
JO - Circulation Research
JF - Circulation Research
IS - 4
ER -