Responses of atrial and aortic baroreceptors to nonhypotensive hemorrhage and to tranfusion

Gupta, PD; Jp, Henry; Sinclair, R. C. F.; Baumgarten, Romain

doi:10.1152/ajplegacy.1966.211.6.1429

Cited by 100 publications

(47 citation statements)

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“…They furthermore substantiate the view of Gupta et al (1966), who suggested that the average discharge rate is the parameter which can be equated with the receptor drive for the central neurones. This is also in line with McKean et al (1970), who argued from information theory that information in spike trains is most likely conveyed in the average count per unit time rather than their instantaneous frequency.…”

Section: Discussionsupporting

confidence: 78%

The physiologically relevant information regarding systemic blood pressure encoded in the carotid sinus baroreceptor discharge pattern.

Arndt¹,

Morgenstern²,

Samodelov³

1977

The Journal of Physiology

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SUMMARY1. The objective was to find out what kind of information regarding systemic blood pressure is transduced by baroreceptors in vivo and how this information is coded in the receptor discharge.2. Carotid sinus pressure, e.c.g., and receptor action potentials were recorded for fifty-two single fibre carotid sinus receptors found in twenty decerebrated unanaesthetized cats. 3. The inflation and gradual deflation of an intraaortic catheter tip balloon manipulated the blood pressure in the carotid sinus in a way as to define the full in vivo stimulus-response curve for each receptor.4. Correlation coefficients were computed between stimulus and response variables for several points on the response curve of each receptor and for every possible combination of stimulus and response variables defined.5. Stimulus variables were (a) systolic, (b) diastolic, (c) mean, (d) pulse pressures and (e) peak positive dP/dt. Response variables were (a) average discharge rate, (b) peak instantaneous frequency, and (c) average burst frequency.6. For every fibre in the sample only the correlations between systolic, diastolic and mean pressures vs. average discharge rate were consistently high and positive. All other correlations were numerically low and/or negative.7. It was concluded that in vivo baroreceptors signal mainly pressure level (systolic, diastolic or mean) as opposed to pulse pressure or dP/dt, and that the average discharge rate is their best index of information content.

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Section: Discussionsupporting

confidence: 78%

The physiologically relevant information regarding systemic blood pressure encoded in the carotid sinus baroreceptor discharge pattern.

Arndt¹,

Morgenstern²,

Samodelov³

1977

The Journal of Physiology

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“…Several possible mechanisms exist for the sympathetic nervous system activation. The decrease in CO observed in both groups receiving endotoxin may have reflexively activated the efferent sympathetic nervous system via a change in arterial baroreceptor tone (41,42). In group I animals, the fall in systemic blood pressure would be expected to activate arterial baroreceptors and thereby lead to an increase in efferent sympathetic activity.…”

Section: Discussionmentioning

confidence: 95%

Dissociation of systemic and renal effects in endotoxemia. Prostaglandin inhibition uncovers an important role of renal nerves.

Henrich¹,

Hamasaki²,

Said³

et al. 1982

J. Clin. Invest.

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A B S T R A C T To elucidate the mechanisms responsible for systemic and renal hemodynamic changes in early endotoxemia, the roles of prostaglandins (PG) and renal nerves were investigated. Endotoxin (E, 3 ag/kg i.v.) was given to two groups of anesthetized dogs that had undergone unilateral renal denervation: Group I (n = 9) E only; Group II (n = 11) E + indomethacin (10 mg/kg i.v.) or meclofenamate (5 mg/kg i.v.). A third group of dogs (Group III, n = 5) received indomethacin (10 mg/kg i.v.) only. 1 h after E in group I dogs, mean arterial pressure (MAP) decreased from 126 to 94 mm Hg (P < 0.001), and prostacyclin (6-keto-Fla metabolite, PGI2) increased (from 0.64 to 2.08 ng/ml, P < 0.005). Glomerular filtration rate (GFR) and renal blood flow (RBF) declined comparably both in innervated and denervated kidneys. In marked contrast, group II dogs had a stable MAP (136-144 mm Hg, NS) and no increase in PGI2 levels. Plasma renin activity (0.7-2.5 ng/ml per h, P < 0.005) increased, and renin secretion was greater in innervated compared with denervated kidneys (255 vs. 74 U/min, P < 0.01) in these PG-inhibited dogs. In addition, denervated kidneys in group II dogs had a greater GFR (42 vs. 34 ml/min, P < 0.01) and RBF (241 vs. 182 ml/min, P < 0.01) than innervated kid- renin activity or PGI2 during the study. These results suggest that PGI2 mediates the systemic hypotension of early endotoxemia in the PG-intact animal. Moreover, PG inhibition uncovers an important effect of E to increase efferent renal nerve activity with a consequent decline in GFR and RBF independent of changes in MAP. Finally, the results demonstrate that renal nerves are important stimuli to renin secretion in early endotoxemia via pathways that are PG-independent.

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“…With respect to the possible effect of VL on the aortic nerve activity, GUPTA et al (1966) found in the dog that an increase in blood volume by 20 % caused a dramatic increase in atrial receptor activity, but little change in single aortic nerve fiber activity. However, KUMADA and SAGAWA (1970) observed in the rabbit that the multifiber aortic nerve activity increased with volume expansion and decreased with hemorrhage.…”

Section: Discussionmentioning

confidence: 99%

“…An increase in the atrial pressure by either VL or distension of the cardiac chambers raises the atrial receptor discharge (GUPTA et al, 1966;THOREN, 1976). HIGGINS et al (1972) observed, in the conscious dog, that both the tachycardic and pressor responses to common carotid occlusion were reduced after the development of congestive heart failure.…”

Section: Discussionmentioning

confidence: 99%

Mechanism of Alteration in Baroreflex Cardiovascular Responses due to Volume Loading

Chen

1978

Jpn.J.Physiol

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The effect and mechanism of volume loading (VL) on the baroreflex sensitivity, in terms of the changes in arterial pressure (AP) and heart rate (HR) to a given change in carotid sinus pressure (CSP), were studied in rabbits anesthetized with chloralose and urethan. The carotid sinuses were vascularly isolated in order to regulate the CSP independently from the systemic arterial pressure. VL was accomplished by intravenous infusion of dextran solution or whole blood to raise the right atrial pressure from 0.4 to 10 cm water. When the CSP was lowered from 90 to 40 mmHg, VL reduced the baroreflex pressor response by 10.1 mmHg (42%) and 19.9 mmHg (46%) before and after aortic nerves section, respectively. The attenuation effect of VL on the carotid pressor response was abolished after cervical vagotomy. VL also reduced the extent of bradycardia and hypotension upon an elevation of CSP from 90 to 140 mmHg. Before aortic nerve section, the reduction by VL was 19.7 beats/min (41%) for the bradycardic response, and 15.1 mmHg (43%) for the depressor response. These attenuation effects of VL were absent after aortic denervation. The results suggest that VL alters the carotid baroreflex pressor response via the vagal afferents subserving the cardiopulmonary receptors, whereas it reduces the depressor and bradycardic responses through the aortic baroreceptor.

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Responses of atrial and aortic baroreceptors to nonhypotensive hemorrhage and to tranfusion

Cited by 100 publications

References 0 publications

The physiologically relevant information regarding systemic blood pressure encoded in the carotid sinus baroreceptor discharge pattern.

The physiologically relevant information regarding systemic blood pressure encoded in the carotid sinus baroreceptor discharge pattern.

Dissociation of systemic and renal effects in endotoxemia. Prostaglandin inhibition uncovers an important role of renal nerves.

Mechanism of Alteration in Baroreflex Cardiovascular Responses due to Volume Loading

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