scholarly journals DIURESIS FROM STIMULATION OF LEFT ATRIAL RECEPTORS: ADH AND THE MALPIGHIAN TUBULES OFRHODNIUS PROLIXUS

1981 ◽  
Vol 66 (3) ◽  
pp. 333-338
Author(s):  
Meryl F. Knapp ◽  
R. J. Linden ◽  
M. Joan Pearson
Keyword(s):  
Left Atrial ◽  
Malpighian Tubules ◽  
Atrial Receptors ◽  
Stimulation Of

"Summation" of the increase in heart rate from stimulation of atrial receptors

1980 ◽  
Vol 58 (6) ◽  
pp. 666-672
Author(s):  
P. V. Greenwood ◽  
C. T. Kappagoda
Keyword(s):  
Heart Rate ◽  
Left Atrial ◽  
Superior Vena ◽  
Right Atrial ◽  
Propranolol Hydrochloride ◽  
Superior Vena Caval ◽  
The Right ◽  
Atrial Receptors ◽  
Stimulation Of ◽  
Wire Cage

In dogs anaesthetized with chloralose, application of stimuli which are likely to activate left atrial (L.A.) and right atrial (R.A.) receptors (complex unencapsulated endings) has been shown to result in an increase in heart rate. The present investigation was undertaken to determine whether the response elicited by the application of one stimulus (i.e., to the left atrium) could be enhanced by the application of a second stimulus (i.e., to the right atrium) in the same animal.The L.A. receptors were stimulated by distending a small balloon at the right upper pulmonary vein-L.A. junction and the R.A. receptors by "expanding" a spherical wire cage positioned at the superior vena caval (S.V.C.)-R.A. junction. Pressures in the S.V.C., R.A., L.A., and femoral artery were measured and the electrocardiogram monitored.In eight dogs stimulation of L.A. receptors resulted in an increase in heart rate (H.R.) of 18.5 beats/min (SEM 6.0; N = 23). In the same animals stimulation of R.A. receptors resulted in an increase in H.R. of 14.6 beats/min (SEM 2.0; N = 25). Application of both stimuli simultaneously resulted in an increase of 32.2 beats/min (SEM 8.0; N = 13). In four dogs propranolol hydrochloride (0.5 mg/kg) markedly diminished the response. In three dogs the response was abolished by bretylium tosylate (10 mg/kg).It is concluded that the increase in H.R. resulting from the application of these two stimuli could be "summated" and these findings support the proposition that the receptors in the two atria act as a functional entity.

scholarly journals Diuresis from left atrial receptors: effect of plasma on the secretion of the Malpighian tubules of Rhodnius prolixus.

1979 ◽  
Vol 291 (1) ◽  
pp. 381-391 ◽  
Author(s):  
C T Kappagoda ◽  
M F Knapp ◽  
R J Linden ◽  
M J Pearson ◽  
E M Whitaker
Keyword(s):  
Left Atrial ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Atrial Receptors

scholarly journals DIURESIS FROM STIMULATION OF LEFT ATRIAL RECEPTORS: INITIAL PURIFICATION STEPS FROM PLASMA OF THE CAUSATIVE AGENT

1981 ◽  
Vol 66 (4) ◽  
pp. 439-445
Author(s):  
Meryl F. Knapp ◽  
R. J. Linden ◽  
M. Joan Pearson ◽  
J. M. Pither ◽  
Elaine M. Whitaker
Keyword(s):  
Causative Agent ◽  
Left Atrial ◽  
Atrial Receptors ◽  
Stimulation Of

Cardiovascular afferent signals and drinking in response to hypotension in dogs

1999 ◽  
Vol 277 (3) ◽  
pp. R795-R801 ◽  
Author(s):  
Terry N. Thrasher ◽  
Craig R. Keenan ◽  
David J. Ramsay
Keyword(s):  
Pulmonary Artery ◽  
Water Intake ◽  
Left Atrial ◽  
Inferior Vena ◽  
Vena Cava ◽  
Ascending Aorta ◽  
Right Atrial ◽  
Arterial Hypotension ◽  
Atrial Receptors ◽  
Stimulation Of

Arterial hypotension stimulates increases in plasma arginine vasopressin (AVP), plasma renin activity (PRA), and water intake in conscious dogs. We have previously reported that increasing left atrial but not right atrial pressure completely blocks the increase in plasma AVP and PRA induced by hypotension. The goal of the present study was to examine the effect of increasing right or left atrial pressure on water intake induced by arterial hypotension. Dogs were prepared with occluding cuffs on the thoracic inferior vena cava, the pulmonary artery, and the ascending aorta. We reduced mean arterial pressure (MAP) 25% below control by either inferior vena cava constriction (IVCC), pulmonary artery constriction (PAC), or ascending aorta constriction (AAC) and measured water intake over a 2-h period. Cumulative water intake during IVCC ( n = 6) and PAC ( n = 6) was 7.8 ± 2.0 and 6.7 ± 2.6 ml/kg, respectively. There was no difference between either the latency or the volume consumed between the two treatments. In contrast, none of the dogs drank during hypotension induced by AAC ( n = 5). Because the degree of arterial baroreceptor unloading was the same in each treatment by design, we conclude that stimulation of left atrial receptors inhibits drinking in response to arterial hypotension but that stimulation of right atrial receptors has no effect on the response in dogs.

scholarly journals THE EFFECTS OF STIMULATION OF THE LEFT ATRIAL RECEPTORS IN THE CAT

1982 ◽  
Vol 67 (4) ◽  
pp. 521-529 ◽  
Author(s):  
Evelyn M. Scott ◽  
A. P. Roberts ◽  
N. M. Tierney
Keyword(s):  
Left Atrial ◽  
Atrial Receptors ◽  
Stimulation Of

Influence of carotid sinus pressure on atrial receptors and renal blood flow

1982 ◽  
Vol 242 (2) ◽  
pp. H220-H226
Author(s):  
F. Karim ◽  
D. U. Mackay ◽  
C. T. Kappagoda
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Left Atrial ◽  
Renal Mass ◽  
Carotid Sinus ◽  
Systemic Arterial Pressure ◽  
Left Pulmonary Vein ◽  
Atrial Receptors ◽  
Sinus Pressure ◽  
Stimulation Of

Stimulation of the atrial receptors results in an increase in renal blood flow. The present investigation was undertaken to determine whether this response was modulated by the input from the baroceptors in the carotid sinus. The experiments were performed on dogs anesthetized with chloralose. The systemic arterial pressure was held constant. The carotid sinuses were perfused at 62 +/- 1.3, 95 +/- 2.7, and 145 +/- 8.3 mmHg. The atrial receptors were stimulated by distension of small balloons positioned at the left pulmonary vein-atrial junctions and the left atrial appendage. At a carotid sinus pressure of 62 +/- 1.3 mmHg, the blood flow increased from 182 +/- 8.5 to 199 +/- 8.9 ml . min-1 . 100 g-1 renal mass. At a carotid sinus pressure of 95 +/- 2.7 mmHg, the blood flow increased from 202 +/- 9.6 to 209 +/- 10.4 ml . min-1 . 100 g-1 renal mass. At a carotid sinus pressure of 145 +/- 8.3 mmHg, the blood flow increased from 237 +/- 13.0 to 239 +/- 12.5 ml . min-1 . 100 g-1 renal mass. The first two responses alone were statistically significant. The response at a carotid sinus pressure of 62 +/- 1.3 mmHg was abolished by cutting or cooling the cervical vagi to 8--10 degrees C. It is concluded that stimulation of the left atrial receptors produces a reflex increase in blood flow to the kidney, and this response is modulated by the input from the carotid sinus baroceptors.

Interaction of left atrial receptors and carotid sinus baroreceptors on heart rate in the dog

1985 ◽  
Vol 248 (5) ◽  
pp. H631-H636 ◽  
Author(s):  
K. K. Teo ◽  
G. C. Man ◽  
C. T. Kappagoda
Keyword(s):  
Heart Rate ◽  
Left Atrial ◽  
Carotid Sinus ◽  
Aortic Pressure ◽  
Response Curves ◽  
Stimulus Response ◽  
Alpha Chloralose ◽  
Atrial Receptors ◽  
Control State ◽  
Stimulation Of

This study was undertaken to determine the influence of 1) the left atrial receptors (LA) on the ability of the carotid sinus baroreceptors (CS) to regulate heart rate and 2) the CS on the reflex increase in heart rate mediated by the LA. The LA were stimulated by stretching the pulmonary vein-atrial junctions in dogs anesthetized with alpha-chloralose. Aortic pressure was controlled, and the pressure in the CS was regulated. Stimulus-response curves were obtained relating heart rate to pressures in the CS, in the control state, and during stimulation of LA (6 dogs). Factorial analysis revealed that LA exerted a significant influence on heart rate (P less than 0.01). Next the CS pressure was set at mid, low, and high levels and the LA stimulated. It was found that the effect on heart rate was greatest at the mid setting (+19.3 +/- 2.9 beats/min) and least at the low setting of the pressure in the CS (+0.9 +/- 0.5, 11 dogs). Sympathetic blockade attenuated significantly the response in the mid setting of the CS pressure and left intact the response at the high setting of the pressure in the CS. It is concluded that there is a significant interaction between these two reflexes.

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