scholarly journals Selective denervation of the aortic and carotid baroreceptors in rats

2019 ◽  
Vol 104 (9) ◽  
pp. 1335-1342
Author(s):  
Jaci A. Castania ◽  
Pedro L. Katayama ◽  
Fernanda Brognara ◽  
Davi J. A. Moraes ◽  
João Paulo J. Sabino ◽  
...  
Keyword(s):  
Carotid Baroreceptors

Identification of carotid vascular receptors that control adrenal catecholamine secretion in dogs

1992 ◽  
Vol 262 (5) ◽  
pp. R872-R878
Author(s):  
W. C. Engeland ◽  
C. D. Zippe ◽  
D. S. Gann
Keyword(s):  
Carotid Sinus ◽  
Carotid Occlusion ◽  
Catecholamine Secretion ◽  
Adrenal Vein ◽  
Carotid Baroreceptors ◽  
Cervical Vagotomy ◽  
Anesthetized Dogs ◽  
Reflex Control ◽  
Adrenal Secretion

The role of carotid sinus and thyrocarotid mechanoreceptors in the reflex control of adrenal medullary function was assessed in anesthetized dogs with adrenal vein catheters. Dogs underwent carotid sinus, thyrocarotid junction, combined carotid sinus and thyrocarotid junction, or sham denervation. On the day after surgery, catecholamine secretion was measured after carotid occlusion proximal to the thyrocarotid junction, cervical vagotomy, and repeat carotid occlusion, each separated by 90 min. After combined carotid denervation, baseline norepinephrine secretion was increased, resulting in a decreased epinephrine-to-norepinephrine ratio. Carotid occlusion before vagotomy did not change the secretion of catecholamines or the epinephrine-to-norepinephrine ratio. After sham carotid denervation, acute vagotomy did not affect catecholamine secretion. However, after denervation of the carotid sinus or thyrocarotid junction, vagotomy resulted in small increases in catecholamine secretion without changing the epinephrine-to-norepinephrine ratio; the magnitude of the response was augmented after combined denervation. At 90 min after vagotomy in dogs with intact carotid baroreceptors, carotid occlusion increased adrenal secretion of catecholamines and decreased the epinephrine-to-norepinephrine ratio. After denervation of carotid sinus or thyrocarotid junction receptors, carotid occlusion increased secretion of catecholamines without changing the epinephrine-to-norepinephrine ratio; the response was abolished by combined denervation. These results show that both carotid sinus and thyrocarotid receptors contribute to the adrenomedullary response to carotid occlusion and to acute vagotomy. Also, reduction in the activity of carotid sinus and thyrocarotid junction receptors chronically (by denervation) or acutely (by carotid occlusion) results in preferential secretion of norepinephrine over epinephrine.

scholarly journals Effects of epinephrine on firing characteristics of two functionally different types of carotid baroreceptors.

1991 ◽  
Vol 69 (4) ◽  
pp. 1097-1105 ◽  
Author(s):  
J L Seagard ◽  
J F van Brederode ◽  
C Dan ◽  
F A Hopp ◽  
E O Elegbe ◽  
...  
Keyword(s):  
Carotid Baroreceptors ◽  
Different Types ◽  
Firing Characteristics

Cardiovascular responses to stimulation of carotid baroreceptors in healthy subjects

1988 ◽  
Vol 75 (2) ◽  
pp. 159-165 ◽  
Author(s):  
R. Hainsworth ◽  
Y. M. H. Al-Shamma
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Cardiovascular Responses ◽  
Pulse Interval ◽  
Healthy Population ◽  
Control Value ◽  
Carotid Baroreceptors ◽  
Single Breath ◽  
Arterial Blood ◽  
Blood Pressures

1. Carotid baroreceptors were stimulated by application of a subatmospheric pressure to a chamber fitted round the anterior and lateral aspects of the subject's neck (neck suction). Pulse interval and heart rate were determined from an electrocardiogram, cardiac output by a single-breath method and arterial blood pressure by an automatic sphygmomanometer. 2. The maximal prolongation of the pulse interval, determined during held expiration, occurred within 2–3 s from the onset of the neck suction. All the measured variables were in steady states between 2 and 3 min from the start of neck suction. 3. Neck suction at − 10 mmHg resulted only in an immediate change in pulse interval. All variables changed approximately linearly with the magnitude of the neck suction between − 10 and − 40 mmHg. 4. The reproducibilities of the responses to neck suction at − 30 mmHg, expressed as two standard deviations of the differences between responses on two occasions, were (mean responses in parentheses): immediate pulse interval, ± 32 (+ 236) ms; steady-state heart rate, ± 2.5 (− 6.5) beats/min; cardiac output ± 0.14 (− 0.59) 1/min; systolic and diastolic blood pressures, ± 10.0 (− 16.9) and ± 5.4 (− 10.1) mmHg, respectively. 5. Control values and responses to neck suction at − 30 mmHg were compared in subjects grouped in four age bands between 19 and 80 years. With increasing age, the control value of cardiac index (cardiac output divided by calculated body surface area) decreased, systolic and diastolic pressures increased, and the responses of all the measured variables to neck suction decreased. These results, obtained from a healthy population, provide reference values for comparison with those of individuals who may have abnormal baroreceptor reflexes.

Effect of carotid or aortic baroreceptor denervation on arterial pressure during hemorrhage in conscious dogs

2001 ◽  
Vol 280 (6) ◽  
pp. R1642-R1649 ◽  
Author(s):  
Terry N. Thrasher ◽  
Cassandra Shifflett
Keyword(s):  
Heart Rate ◽  
Standard Deviation ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Conscious Dogs ◽  
Carotid Baroreceptors ◽  
Intact Condition ◽  
Aortic Baroreceptors

We studied the effect of chronically denervating aortic baroreceptors (ABR; n = 6) or carotid baroreceptors (CBR; n= 7) on mean arterial pressure (MAP) and heart rate (HR) responses to hemorrhage in the dog. Neither denervation had a significant effect on basal MAP, the variability (standard deviation) of MAP, or resting HR. However, the breakpoint of MAP (defined as the volume of blood removed when MAP fell more than 10% below control and declined monotonically thereafter) was significantly reduced in dogs with only ABR functional (12.4 ± 1.4 ml/kg) compared with the volume in the intact condition (18.9 ± 1.8 ml/kg). In contrast, there was no difference in the breakpoint or the MAP at any time during hemorrhage in dogs with both CBR functional compared with their intact responses. In a different group of dogs ( n = 6), responses were determined with both CBR operating and again after unilateral denervation, leaving only one CBR (1CBR) functional. Basal MAP and the variability of MAP were not altered in dogs with only 1CBR functional, but the breakpoint (11.7 ± 1.4 ml/kg) during hemorrhage was significantly different compared with responses with two CBR (21.2 ± 2.3 ml/kg), and MAP fell to much lower levels. These results indicate that the CBR can compensate fully for loss of ABR during hemorrhage but not vice versa; and bilateral CBR inputs are required for normal responses to hemorrhage.

Baroreceptor output during normal and obstructed breathing and Mueller maneuvers

1981 ◽  
Vol 240 (5) ◽  
pp. H721-H729 ◽  
Author(s):  
R. S. Fitzgerald ◽  
J. L. Robotham ◽  
A. Anand
Keyword(s):  
Blood Pressure ◽  
Systolic Pressure ◽  
Intrathoracic Pressure ◽  
Inspiratory Effort ◽  
Carotid Baroreceptors ◽  
Cardiac Responses ◽  
Inspiratory Phase ◽  
Mueller Maneuver ◽  
Aortic Baroreceptors ◽  
Anesthetized Cat

Cardiovascular control during asthma and other forms of obstructed breathing has not been extensively investigated. Previous studies in dogs have shown that obstructed breathing or an inspiratory effort against a blocked airway (Mueller maneuver) provoke large oscillations in blood pressure. During the inspiratory phase transmural systolic pressure relative to atmosphere drops initially, but transmural systolic pressure relative to intrathoracic pressure can remain unchanged or even increase. Because the carotid baroreceptors are located in the extrathoracic circulation, whereas the aortic baroreceptors are located in the intrathoracic circulation, and each responds to local transmural arterial pressure, simultaneous baroreceptor output from these two areas was measured in the anesthetized cat during normal and obstructed breathing and during Mueller maneuvers. Both whole-nerve and single-fiber preparations showed a significantly decreased output from the carotid baroreceptors during obstructed inspiratory efforts, whereas aortic baroreceptor output decreased significantly less or not at all. Transmural systolic pressure decreased significantly less in the aorta than in the carotid regions. Further, the aortic baroreceptors were more sensitive to changes in pulse pressure than were the carotid baroreceptors. These results suggest a mechanism for stabilizing the cardiac responses to precipitous falls in blood pressure that occur in obstructed breathing.

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