scholarly journals Effects of left atrial receptor stimulation on carotid chemoreceptor-induced renal responses in dogs.

1992 ◽  
Vol 456 (1) ◽  
pp. 529-539 ◽  
Author(s):  
F Karim ◽  
M al-Obaidi
Keyword(s):  
Left Atrial ◽  
Receptor Stimulation ◽  
Atrial Receptor ◽  
Renal Responses

Atrial and arterial baroreceptor influences on the circulatory response to acute changes in renal perfusion

1993 ◽  
Vol 71 (7) ◽  
pp. 425-431
Author(s):  
N. Ashton ◽  
A. J. Rankin
Keyword(s):  
Vascular Resistance ◽  
Left Atrial ◽  
Perfusion Pressure ◽  
Carotid Sinus ◽  
Renal Perfusion ◽  
Receptor Stimulation ◽  
Renal Perfusion Pressure ◽  
Atrial Receptor ◽  
Acute Changes ◽  
Atrial Receptors

We have recently reported a neurally mediated reflex increase in hindlimb vascular resistance associated with an acute decrease in renal perfusion pressure in the chloralose–urethane-anesthetized rabbit. The present study was designed to investigate the influence of this reflex in the body's integrated response to circulatory disturbances by investigating the influence of carotid baroreceptor and left atrial receptors on this reflex and assessing the effect of acute changes in renal perfusion on the heart. Interaction of the renal-generated reflex with carotid baroreceptors was investigated by independent perfusion of the carotid sinus region. Responses in hindlimb perfusion pressure, at constant flow, to changes in renal perfusion were greatest with the carotid sinus perfusion pressure (CSP) low (27 ± 4 mmHg (1 mmHg = 133.3 Pa) increase in hindlimb pressure at low CSP vs. 19 ± 3 mmHg increase at normal CSP) and were inhibited with maximum carotid stimulation. Partial mitral obstruction, resulting in left atrial distension and atrial receptor stimulation, attenuated the hindlimb vascular response. The increase in hindlimb pressure under control conditions was 34 ± 10 mmHg compared with 20 ± 5 mmHg during atrial receptor stimulation. However, acute reduction of renal perfusion pressure did not result in any changes in heart rate, cardiac output, or inotropic state. It appears that both atrial and arterial baroreflexes modify the reflex change in hindlimb vascular resistance associated with acute alterations of renal perfusion.Key words: afferent renal nerves, baroreceptors, atrial receptors, vascular resistance.

Characterization of the histamine receptors in rabbit left atria

1981 ◽  
Vol 59 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Alicia Polanin ◽  
John H. McNeill
Keyword(s):  
Left Atrial ◽  
Histamine Receptor ◽  
Histamine Receptors ◽  
Receptor Blockade ◽  
Inotropic Response ◽  
Receptor Stimulation ◽  
Inotropic Effects ◽  
Receptor Antagonism ◽  
Positive Inotropic Effects

The effects of selective histamine receptor analogs were studied in electrically paced rabbit left atria. Atrial tension was increased by histamine (an H1 and H2 agonist), 4-methylhistamine and impromidine (H2 agonists), and 2-pyridylethylamine (PEA) (an H1 agonist). The responses to histamine and impromidine were not altered by propranolol (1 × 10−7 M) or reserpine pretreatment. However, the responses to 4-methylhistamine and PEA were significantly decreased upon pretreatment with propranolol or reserpine. Promethazine pretreatment (H1 receptor blockade) antagonized the inotropic effects of histamine and PEA but had no effect on the responses to 4-methylhistamine or impromidine. Cimetidine pretreatment (H2 receptor antagonism) competitively blocked the positive inotropic effects of histamine, 4-methylhistamine, and impromidine. These results suggest that the left atrial inotropic response is mediated through H1 and H2 receptor stimulation.

scholarly journals Left Atrial Receptor Discharge during Atrial Arrhythmias in the Dog

1973 ◽  
Vol 33 (6) ◽  
pp. 672-677 ◽  
Author(s):  
IRVING H. ZUCKER ◽  
JOSEPH P. GILMORE
Keyword(s):  
Left Atrial ◽  
Atrial Arrhythmias ◽  
Atrial Receptor

Increased left atrial pressure does not alter renal function in the conscious primate

1982 ◽  
Vol 243 (1) ◽  
pp. R119-R124
Author(s):  
K. G. Cornish ◽  
J. P. Gilmore
Keyword(s):  
Blood Volume ◽  
Nonhuman Primate ◽  
Left Atrial ◽  
Macaca Fascicularis ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Blood Volume Expansion ◽  
Stretch Receptors ◽  
Renal Responses

To study the functional role of the atriorenal reflex in the nonhuman primate, we chronically instrumented six Macaca fascicularis with left atrial snares and left atrial and aortic catheters. After inserting a bladder catheter, we determined hemodynamic and renal responses of the conscious chair-restrained monkey to increased left atrial pressure. In 23 snare experiments, no significant changes in renal or cardiovascular function were observed even though left atrial pressure increased from 6.5 +/- 3.3 to 16.2 +/- 3.4 mmHg. The animals were subjected also to blood volume expansion with isoncotic isotonic dextran solutions (+15% of calculated blood volume). They responded normally to this volume stimulus. Conscious dogs prepared in the same manner as the nonhuman primate exhibited diuresis in response to elevations of atrial pressure. We conclude that left atrial stretch receptors are not importantly involved in volume homeostasis in the nonhuman primate.

V1- and V2-receptor contributions to ovine fetal renal and cardiovascular responses to vasopressin

1992 ◽  
Vol 262 (4) ◽  
pp. R636-R643
Author(s):  
M. G. Ervin ◽  
M. G. Ross ◽  
R. D. Leake ◽  
D. A. Fisher
Keyword(s):  
Receptor Agonist ◽  
Urine Osmolality ◽  
Cardiovascular Responses ◽  
Urine Flow ◽  
Receptor Blockade ◽  
Fetal Life ◽  
Receptor Stimulation ◽  
V2 Receptor ◽  
Ovine Fetal ◽  
Renal Responses

To assess the contributions of arginine vasopressin (AVP) V1- and V2-receptors to the ovine fetal responses to AVP, we studied V2-receptor stimulation in the presence of V1-receptor blockade, and selective V2-receptor stimulation in chronically catheterized fetal lambs. AVP administration (20 ng/kg) to the saline infused fetuses (n = 8; 132 +/- 2 days) significantly increased mean arterial pressure (MAP; 45 +/- 2 to 53 +/- 4 mmHg) and urine osmolality (Uosm; 134 +/- 13 to 379 +/- 42 mosmol/kgH2O) and decreased heart rate (HR; 168 +/- 3 to 147 +/- 5 beats/min) and urine flow (V; 0.48 +/- 0.10 to 0.19 +/- 0.03 ml/min). V1-receptor antagonist infusion, [d(CH2)5,Tyr(Me)]AVP (n = 7; 134 +/- 1 days) had no effect on fetal MAP, Uosm, HR, or V. V1-receptor blockade abolished the MAP response to AVP without affecting the HR and urinary responses. In a second series of animals (n = 6; 131 +/- 1 days), selective V2-receptor agonist infusion [desmopressin (DDAVP)] had no effect on fetal MAP or HR while initial changes in V and Uosm were identical to the effects of AVP alone. Our results demonstrate clear discrimination of V1- and V2-receptor-mediated events in the fetal MAP and renal responses to AVP. Moreover, the HR response to AVP is not mediated by the population of V1-receptors blocked by [d(CH2)5,Tyr(Me)]AVP or V2-receptors stimulated by DDAVP, suggesting the presence of additional AVP receptor subclass(es) during fetal life.

scholarly journals Does gender influence human cardiovascular and renal responses to water immersion?

2000 ◽  
Vol 89 (2) ◽  
pp. 621-628 ◽  
Author(s):  
Donald E. Watenpaugh ◽  
Bettina Pump ◽  
Peter Bie ◽  
Peter Norsk
Keyword(s):  
Body Mass ◽  
Left Atrial ◽  
Water Immersion ◽  
Urine Volume ◽  
Random Order ◽  
Cardiovascular Responses ◽  
Gender Influence ◽  
Significant Difference ◽  
Renal Responses ◽  
Sodium And Potassium

We hypothesized that women and men exhibit similar cardiovascular and renal responses to thermoneutral water immersion (WI) to the neck. Ten women and nine men underwent two sessions in random order: 1) seated nonimmersed for 5.5 h (control) and 2) WI for 3 h, with subjects seated nonimmersed for 1.5 h pre- and 1 h postimmersion. We measured left atrial diameter, heart rate, arterial pressure, urine volume and osmolality, and urinary endothelin, urodilatin, sodium, and potassium excretion. No significant difference existed between groups in cardiovascular responses. The groups also exhibited mostly similar renal responses to immersion after adjustment for body mass. However, female urodilatin excretion per kilogram during immersion was over twofold that of men, and the female kaliuretic response to immersion was delayed and less pronounced relative to that in men. Men may excrete more potassium than women during immersion because men possess greater lean body mass (potassium per kilogram). Results obtained in men during WI may be cautiously extrapolated to women, yet urodilatin and potassium responses exhibit gender differences.

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