Arteriovenous Difference of the Blood Density in the Coronary Circulation

1985 ◽  
Vol 107 (1) ◽  
pp. 34-40 ◽  
Author(s):  
T. Kenner ◽  
M. Moser ◽  
W. Mohl
Keyword(s):  
Density Gradient ◽  
Coronary Sinus ◽  
Venous Pressure ◽  
Fluid Loss ◽  
Fluid Exchange ◽  
Arterial Blood ◽  
Extravascular Fluid ◽  
Anesthetized Dogs ◽  
Blood Density

The mechanical oscillator technique permits determining blood density continuously with high accuracy. Using this technique arteriovenous density gradients were recorded in the coronary vascular bed of anesthetized dogs. It was found that the coronary sinus blood has a higher density than arterial blood due to the loss of filtered fluid in the microcirculation. The amount of fluid loss corresponds to the lymph flow in the myocardium. Increase of venous pressure leads to an increase of the density gradient. Intermittent coronary sinus occlusion (ICSO) surprisingly leads to a reduction of the density gradient. Injection of osmotically hypertensive fluids influences the arteriovenous gradient by shifting extravascular fluid into the blood. The method permits the determination of filtration coefficients and to estimate the tissue volume available for fluid exchange.

Effect of norepinephrine on plasma free fatty acids in dogs treated with reserpine

1963 ◽  
Vol 205 (1) ◽  
pp. 57-59 ◽  
Author(s):  
Francois M. Abboud ◽  
Michael G. Wendling ◽  
John W. Eckstein
Keyword(s):  
Blood Pressure ◽  
Fatty Acids ◽  
Free Fatty Acids ◽  
Arterial Blood Pressure ◽  
Pressor Response ◽  
Maximal Increase ◽  
Arterial Blood ◽  
Anesthetized Dogs ◽  
Plasma Ffa

Some adrenergic blocking drugs reduce the mobilization of free fatty acids (FFA) in response to administration of catecholamines. The present experiments were done to see if potentiation of the pressor effect of norepinephrine by reserpine is accompanied by a greater increase in plasma FFA. Norepinephrine was infused intravenously into 16 anesthetized dogs. Eight of them had been treated with reserpine, 0.25 mg/kg daily, intraperitoneally for 2 days; the others were not treated. Arterial blood samples were drawn before, during, and after norepinephrine for determination of plasma FFA concentrations. Systemic arterial blood pressure was measured continuously. In the treated animals the maximal increase in arterial blood pressure as well as the progressive increments in FFA concentration were greater than in the untreated dogs. The experiments indicate that potentiation of the pressor response to norepinephrine after reserpine is accompanied by a greater FFA response.

Effects of albumin infusion on renal function in the dog

1963 ◽  
Vol 205 (1) ◽  
pp. 153-161 ◽  
Author(s):  
Mary Jo Elpers ◽  
Ewald E. Selkurt
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Renal Plasma Flow ◽  
Venous Pressure ◽  
Venous Blood ◽  
Urine Volume ◽  
Albumin Infusion ◽  
Arterial Blood ◽  
Vasa Recta ◽  
Anesthetized Dogs

Serum albumin (25%) was infused into anesthetized dogs undergoing a saline diuresis. No significant effect was seen on arterial pressure, but renal venous pressure was elevated slightly. GFR remained unchanged, while Cpah, renal plasma flow, total renal blood flow, and flow to medullary tissue increased significantly. Accompanying these changes were marked declines in PAH and creatinine extraction ratios. Urine volume, Cna, and Cosm declined appreciably during albumin infusion; TcHH2O tended to decrease. The ratio of Na and osmolar constituents in renal venous blood to that in arterial blood increased above unity, and calculations indicated that at this time Na was washed from the kidney. Tmpah remained unchanged during albumin infusion. It is concluded that during albumin infusion, there is an increase in plasma volume and renal blood flow accompanied by a diversion of part of this blood through aglomerular regions, possibly through A-V anastomoses, as evidenced by the accompanying decrease in Ecr and Epah. This could involve increased perfusion of the medullary papillary zone, including the vasa recta vessels, supported by the observations that during albumin infusion there is a washout of osmotic constituents, primarily Na, presumably from a zone of high Na concentration.

Effect of a left atrium-pulmonary vein baroreflex on peripheral vascular beds

1977 ◽  
Vol 233 (5) ◽  
pp. H587-H591 ◽  
Author(s):  
T. C. Lloyd ◽  
J. J. Fried
Keyword(s):  
Left Atrial ◽  
Venous Pressure ◽  
Peripheral Resistance ◽  
Radioactive Microspheres ◽  
Peripheral Vascular ◽  
Blood Flows ◽  
Arterial Blood ◽  
Anesthetized Dogs ◽  
Response Peak ◽  
Vascular Beds

A step increase of left atrial and pulmonary venous pressure from 0 to 25 mmHg was used in anesthetized dogs with controlled arterial blood pressure to generate reflex systemic vasodilation. The resultant response of total peripheral resistance was an initial transient fall of about 40% which spontaneously regressed while the stimulus was maintained. Injections of differently tagged radioactive microspheres were used to measure selected organ blood flows prior to raising atrial pressure, at the response peak, during the steady state, and after recovery. Resistances of skin, skeletal muscle, kidney, and large intestine significantly fell upon atriovenous distention. The response in muscle, which greatly exceeded that of the other organs, was not sustained, whereas resistances of other responding beds remained depressed until the stimulus was removed. No significant responses occurred in small intestine, liver (hepatic artery), or adrenal gland.

Circulating plasma volume changes in anesthetized dogs during positive pressure breathing

1959 ◽  
Vol 14 (6) ◽  
pp. 937-939 ◽  
Author(s):  
S. Sobel ◽  
S. F. Marotta ◽  
J. P. Marbarger
Keyword(s):  
Mean Arterial Pressure ◽  
Plasma Volume ◽  
Venous Pressure ◽  
Positive Pressure ◽  
Fluid Loss ◽  
Progressive Decrease ◽  
Volume Changes ◽  
Alkaline Urine ◽  
Anesthetized Dogs ◽  
Pressure Changes

Various circulatory functions were measured in anesthetized dogs subjected to 18.5 mm Hg positive pressure breathing. Immediately upon raising the intrapulmonary pressure there occurred a five- to sixfold increase in venous pressure as well as a decrease in mean arterial pressure. Accompanying these pressure changes was a progressive decrease in circulating plasma volume as measured by the T-1824 method. A 30% decrease in plasma volume was recorded after 160 minutes of increased intrapulmonary pressure. Hemoconcentration was also indicated by the increased hematocrits, although calculated fluid loss was only 13%. All circulatory changes returned to prepressure breathing levels upon release of pressure breathing. Other changes, such as oliguria, periods of apnea and an alkaline urine accompanied positive pressure breathing. The data suggest that the decrease in plasma volume is the result of venostasis caused by the rapid increase in venous pressure. Submitted on April 27, 1959

On venous pressure in arterial and "isolated" venous hypertension

1927 ◽  
Vol 23 (6-7) ◽  
pp. 632-640
Author(s):  
P. N. Nikolaev
Keyword(s):  
Blood Pressure ◽  
Arterial Blood Pressure ◽  
Venous Pressure ◽  
Venous Blood ◽  
Venous Hypertension ◽  
Clinical Use ◽  
Arterial Blood

If the determination of arterial blood pressure has entered clinical use as an indispensable method for the recognition and interpretation of various diseases, the same cannot be said about the determination of venous blood pressure. Only the first steps are still being taken.

scholarly journals Should we stop using the determination of central venous pressure as a way to estimate cardiac preload?

2012 ◽  
pp. 181-184 ◽  
Author(s):  
Johann Smith Ceron Arias ◽  
Manuel Felipe Muñoz Nañez
Keyword(s):  
Central Venous Pressure ◽  
Blood Volume ◽  
Pulse Pressure ◽  
Venous Pressure ◽  
Pressure Change ◽  
Cardiac Preload ◽  
Central Venous ◽  
End Diastolic Volume ◽  
Dynamic Variables

The determination of the values of central venous pressure has long been used as a guideline for volumetric therapy in the resuscitation of the critical patient, but the performance of such parameter is currently being questioned as an effective measurement of cardiac preload. This has aroused great interest in the search for more accurate parameters to determine cardiac preload and a patient’s blood volume. Goals and Methodology: Based on literature currently available, we aim to discuss the performance of central venous pressure as an effective parameter to determine cardiac preload. Results and Conclusion: Estimating variables such as end-diastolic ventricular area and global end-diastolic volume have a better performance than central venous pressure in determining cardiac preload. Despite the best performance of these devices, central venous pressure is still considered in our setting as the most practical and most commonly available way to assess the patient’s preload. Only dynamic variables such as pulse pressure change are superior in determining an individual’s blood volume.

Basic determinants of epicardial transudation

1997 ◽  
Vol 273 (3) ◽  
pp. H1408-H1414 ◽  
Author(s):  
R. H. Stewart ◽  
D. A. Rohn ◽  
S. J. Allen ◽  
G. A. Laine
Keyword(s):  
Reflection Coefficient ◽  
Coronary Sinus ◽  
Myocardial Edema ◽  
Hydraulic Conductance ◽  
Linear Increase ◽  
Left Ventricular ◽  
Edema Formation ◽  
Anesthetized Dogs ◽  
The Difference ◽  
Osmotic Reflection Coefficient

Myocardial edema formation, which has been shown to compromise cardiac function, and increased epicardial transudation (pericardial effusion) have been shown to occur after elevation of myocardial venous and lymphatic outflow pressures. The purposes of this study were to estimate the hydraulic conductance and osmotic reflection coefficient for the epicardium and to determine the effect of coronary sinus hypertension and cardiac lymphatic obstruction on epicardial fluid flux (JV,e/Ae). A Plexiglas hemispheric capsule was attached to the left ventricular epicardial surface of anesthetized dogs. JV,e/Ae was determined over 30-min periods for three intracapsular pressures (-5, -15, and -25 mmHg) and two intracapsular solutions exerting colloid osmotic pressures of 7.0 and 2.0 mmHg. Hydraulic conductance was estimated to be 3.7 +/- 0.5 microliters.h-1.cm-2.mmHg-1. An osmotic reflection coefficient of 0.9 was calculated from the difference in JV,e/Ae of 16.5 +/- 8.4 microliters.h-1.cm-2 between the two solutions. Graded coronary sinus hypertension induced a linear increase in JV,e/Ae, which was significantly greater in dogs without cardiac lymphatic occlusion than in those with occlusion.

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