Effect of arachidonic acid and indomethacin on renal function of dogs with pericardial tamponade

1981 ◽  
Vol 59 (6) ◽  
pp. 586-594 ◽  
Author(s):  
Robert J. Boudreau ◽  
Henry Mandin
Keyword(s):  
Blood Flow ◽  
Arachidonic Acid ◽  
Arterial Pressure ◽  
Plasma Protein ◽  
Sodium Excretion ◽  
Protein Concentration ◽  
Venous Pressure ◽  
Pericardial Tamponade ◽  
Renin Activity ◽  
Plasma Protein Concentration

Previous studies revealed persistent sodium retention in dogs with chronic pericardial tamponade (induced by injection of Freund adjuvant into pericardial sacs) and pericardiocentesis, revealed in increased sodium excretion. Three groups of dogs were studied. Group 1 was treated with indomethacin (2.5 mg/kg, iv) prior to pericardiocentesis. Compared with experiments without indomethacin, sodium excretion did not increase following pericardiocentesis in animals treated with indomethacin despite similar changes in arterial pressure, venous pressure, hematocrit, plasma protein concentration, and renin activity. This effect of indomethacin was presumably mediated through prostaglandin (PG) synthesis inhibition. Group 2 dogs received an infusion of arachidonic acid (AA) (to increase PG synthesis) into the left renal artery (20 μg∙kg−1∙min−1). Sodium excretion increased after AA infusion during tamponade (11.2 to 30.9 mequiv∙min−1) with a further increase occurring after pericardiocentesis (84.4 mequiv.∙min−1). Animals in group 3 were infused with both 20 and 80 μg∙kg−1∙min−1 doses of AA. Although sodium excretion following 80 μg∙kg−1∙min−1 AA (21 mequiv.∙min−1) was higher than that seen during 20 μg∙kg−1∙min−1 (14.2 mequiv.∙min−1), a further increase in sodium excretion to 45.6 mequiv.∙min−1 followed pericardiocentesis. During tamponade, AA did not change any of the measured parameters other than sodium excretion, a result compatible with the proposed distal tubular site of action of PG. Absolute but not fractional cortical blood flow distribution increased during the time sodium excretion increased following pericardiocentesis in all experiments. It is proposed that increased PG synthesis may be one possible mechanism involved in the natriuresis seen following pericardiocentesis. One cannot exclude the possibility that increased absolute blood flow to the superficial cortex also contributes to the observed natriuresis. Changes in arterial pressure, venous pressure, hematocrit, plasma protein concentration, and renin activity appear to contribute to the observed natriuresis but only when PG synthesis is not blocked.

Influence of the plasma protein concentration on renal function

1991 ◽  
Vol 80 (5) ◽  
pp. 427-433 ◽  
Author(s):  
Allan D. Cumming ◽  
Adam Linton
Keyword(s):  
Renal Function ◽  
Pulmonary Artery ◽  
Arterial Pressure ◽  
Plasma Protein ◽  
Sodium Excretion ◽  
Protein Concentration ◽  
Experimental Studies ◽  
Plasma Osmolality ◽  
Sodium Reabsorption ◽  
Plasma Protein Concentration

1. The effect of the plasma protein concentration on renal function remains controversial. Most, but not all, experimental studies suggest that a reduced plasma protein concentration perfusing the kidney may reduce tubular sodium reabsorption. Hypoproteinaemic disease states are usually associated with sodium retention, which is not always volume-dependent. 2. We induced a 21% and 24% reduction in plasma total protein and plasma albumin, respectively, in unanaesthetized sheep by acute extracorporeal plasmapheresis. Arterial pressure did not change, and changes in circulatory volume were minimised by infusion of crystalloid to maintain pulmonary artery occlusion pressure, measured using a Swann-Ganz pulmonary artery catheter. 3. After plasmapheresis, there was no significant change in creatinine clearance, sodium excretion, plasma renin activity or urinary kallikrein excretion. 4. After plasmapheresis, there was a significant reduction in plasma osmolality, increase in urine osmolality and fall in free water clearance. 5. The results suggest that in the absence of detectable changes in circulating volume or arterial pressure, acute hypoproteinaemia is associated with significant changes in renal water handling, but has no direct effect on sodium excretion or on renal release of renin and kallikrein.

Urinary kallikrein and systemic prostacyclin synthesis during sodium chloride infusion in normal man

1985 ◽  
Vol 68 (5) ◽  
pp. 537-543 ◽  
Author(s):  
M. L. Watson ◽  
A. D. Cumming ◽  
A. T. Lambie ◽  
J. A. Oates
Keyword(s):  
Sodium Chloride ◽  
Plasma Renin Activity ◽  
Plasma Protein ◽  
Sodium Excretion ◽  
Protein Concentration ◽  
Plasma Renin ◽  
Urine Flow ◽  
Renin Activity ◽  
Urinary Kallikrein ◽  
Plasma Protein Concentration

1. An intravenous infusion of 3 litres of sodium chloride solution (saline: 150 mmol/l) was given over 1 h to normal subjects. 2. During and immediately after the infusion, renal plasma flow increased in the majority of subjects, but the rise was not statistically significant. Significant increases in urine flow, sodium excretion, urinary kallikrein excretion and urinary excretion of dinor-6-keto prostaglandin (PG) F1α, a measure of systemic PGI2 synthesis, were noted. Plasma renin activity and plasma protein concentration were significantly lowered by the infusion. 3. At 2 h after the end of the infusion, although urine flow fell significantly, sodium excretion had not decreased. The reduction in plasma renin activity and plasma proteins persisted, and excretion of kallikrein and the PGI2 metabolite returned to control values. 4. Overall, urinary kallikrein excretion correlated significantly with urine flow and with sodium excretion. Peak kallikrein excretion occurred in the second 30 min of the infusion, and preceded maximal urine flow and sodium excretion. 5. The results suggest that increased systemic synthesis of PGI2 occurs in response to an acute infusion of sodium chloride, and may be an adaptive response of the vasculature to volume expansion. They support a role for the renal kallikrein-kinin system in the early diuretic and natriuretic response to saline infusion; the reduction in plasma renin activity and plasma protein concentration may be involved in both the early response and the persistent natriuresis 2 h after the infusion.

Cardiac edema in dogs: Distribution of renal blood flow and glomerular filtrate

1979 ◽  
Vol 57 (1) ◽  
pp. 71-77
Author(s):  
Robert J. Boudreau ◽  
Henry Mandin
Keyword(s):  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Renal Blood Flow ◽  
Plasma Protein ◽  
Protein Concentration ◽  
Filtration Rate ◽  
Pericardial Tamponade ◽  
Plasma Protein Concentration ◽  
Glomerular Filtrate

The injection of Freund's adjuvant into the pericardial sac of 29 dogs resulted in chronic pericardial tamponade with persistent sodium retention. Micropuncture, clearance, and radioactive microsphere experiments were initiated 6–13 days after pericardial injection and 60 min after pericardiocentesis. Pericardiocentesis increased sodium excretion (from 12.2 to 41.3 μequiv./min) and mean arterial pressure (+ 20 mmHg (1 mmHg = 133.322 Pa)). Central venous pressure decreased 6.5 mmHg, as did hematocrit (from 45.7 to 39.8%) and plasma protein concentration (from 5.88 to 5.15 g%). Pericardiocentesis had no significant effect on renal blood flow (RBF), nor plasma flow. Redistribution of glomerular filtrate was suggested by the observation that superficial nephron glomerular filtration rate increased (from 91 to 108 nL/min) while glomerular filtration rate remained unaltered. Determination of intrarenal distribution of RBF revealed that cortical blood flow also distributed superficially. A significant increase in the fraction of RBF perfusing zone 1 (outer cortex) and a decrease in fractional perfusion of zones 2, 3, and 4 (juxtamedullary cortex) were observed in each experiment following pericardiocentesis. RBF distribution examined in a series of six animals prior to and during the development of pericardial tamponade showed the opposite effect.These results indicate that pericardiocentesis causes redistribution of both glomerular filtrate and RBF to superficial nephrons. The development of pericardial tamponade was associated with increased fractional juxtamedullary blood flow. These changes may have been the result of altered blood pressure, hematocrit, plasma protein concentration, or altered renal resistance.

Effects of hypoproteinemia on fluid volumes and arterial pressure

1983 ◽  
Vol 245 (2) ◽  
pp. H284-H293 ◽  
Author(s):  
R. D. Manning ◽  
A. C. Guyton
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Plasma Renin Activity ◽  
Blood Volume ◽  
Plasma Protein ◽  
Plasma Volume ◽  
Protein Concentration ◽  
Plasma Renin ◽  
Renin Activity ◽  
Plasma Protein Concentration

The effects of both moderate and large decreases in plasma protein concentration on arterial pressure and fluid volumes were studied in 23 conscious dogs. In experiment 1, plasma protein concentration decreased 33% during a 5-day plasmapheresis period. During this time sodium space increased 11%, mean arterial pressure decreased slightly, and neither blood volume nor plasma volume decreased. Experiment 2 was performed to see if blockade of the alpha-sympathetic and angiotensin systems could prevent the blood volume homeostasis during moderate hypoproteinemia. Sodium space increased; however, blood volume was unchanged. During experiment 3 plasma protein concentration decreased 68% over a 12-day plasmapheresis period. By the last day of plasmapheresis, plasma protein concentration was 2.4 g/100 ml, mean arterial pressure had decreased 26 mmHg, sodium space had increased 12%, plasma renin activity had increased 11-fold, and blood volume and plasma volume were 63.9 +/- 4.0 and 66.9 +/- 2.5% of control, respectively. We conclude that the maintenance of a normal blood volume during moderate hypoproteinemia does not require active participation of the renin-angiotensin and alpha-sympathetic systems and large decreases in plasma protein concentration are accompanied by marked hypovolemia, hypotension, and hyperreninemia.

Studies on Ultrafiltration in Peritoneal Dialysis: Influence of Plasma Proteins and Capillary Blood Flow

1986 ◽  
Vol 6 (2) ◽  
pp. 93-98 ◽  
Author(s):  
Claudio Ronco ◽  
Alessandra Brendolan ◽  
Luisa Bragantini Stefano ◽  
Chiaramonte Mariano ◽  
Feriani Aldo Fabris ◽  
...  
Keyword(s):  
Blood Flow ◽  
Peritoneal Dialysis ◽  
Plasma Protein ◽  
Protein Concentration ◽  
Capillary Blood ◽  
Capillary Blood Flow ◽  
Transmembrane Pressure ◽  
Ultrafiltration Rate ◽  
Filtration Fraction ◽  
Plasma Protein Concentration

This study has evaluated the influence of peritoneal blood flow and plasma protein concentration on the peritoneal ultrafiltration rate. In vitro and in vivo experiments were done to assess the effective peritoneal capillary blood flow. Based on the assumption that one can compare the behavior of an hollow fiber hemofilter with the peritoneal dialysis system, we have compared the opera tional characteristics of the two systems. After demonstrating that there was filtration pressure equilibrium in the filter, the plasma protein concentration was measured in the venous site of the filter at different applied transmembrane pressures. The nomogram, so obtained, was used to calculate the plasma-protein concentration in the blood leaving the peritoneal capillary during exchanges with an established glucose concentration (and therefore at a given transmembrane pressure), and to calculate the filtration fraction. Once that fraction had been calculated, based on the value of the ultrafiltration rate, one can calculate the importance of the plasma flow and then the blood flow. In this study the filtration fraction ranged between 45 and 55% and the blood flow ranged between 21 and 27 ml/min. It was concluded that the blood flow may be very low and hence may limit ultrafiltration.

Effects of hypoproteinemia on blood volume and arterial pressure of volume-loaded dogs

1990 ◽  
Vol 259 (5) ◽  
pp. H1317-H1324
Author(s):  
R. D. Manning
Keyword(s):  
Body Weight ◽  
Arterial Pressure ◽  
Blood Volume ◽  
Plasma Protein ◽  
Protein Concentration ◽  
Control Period ◽  
Plasma Protein Concentration ◽  
Autologous Plasma ◽  
Protein Mass

Studies were performed in 14 conscious, anephric dogs to clarify the role of blood volume in the genesis of hypertension. The dogs were splenectomized and had plasma protein concentration (PPC) reduced to 2.7 g/dl by daily plasmapheresis for 9 days. This hypoproteinemia resulted in a 20% decrease in both blood volume and mean arterial pressure. On the 10th day the dogs were nephrectomized. On the 11th day after a 3-h control period with plasmapheresis, lactated Ringer equivalent to 10 or 20% of body weight was intravenously infused. By 25 h postinfusion blood volume had not increased, and the dogs were still hypotensive. At 25 h plasma protein mass was returned to normal by intravenous infusion of autologous plasma, the average blood volume of the three low PPC groups increased approximately 50%, and the arterial pressure increased greater than 60%. The decrease in PPC shifted the regression of blood volume on sodium space down the blood volume axis. In conclusion, the dependence of arterial pressure on blood volume was demonstrated by the decrease in both blood volume and arterial pressure after PPC reduction, the constancy of blood volume and pressure during Ringer infusion, and the increase in both volume and pressure after plasma infusion.

Effect of hemolysis on reflection coefficient determined by endogenous blood indicators

1987 ◽  
Vol 62 (6) ◽  
pp. 2252-2257 ◽  
Author(s):  
M. B. Maron ◽  
C. F. Pilati ◽  
K. C. Maender
Keyword(s):  
Reflection Coefficient ◽  
Plasma Protein ◽  
Protein Concentration ◽  
Venous Pressure ◽  
Hemoglobin Concentration ◽  
Plasma Protein Concentration ◽  
Fluid Filtration ◽  
Lung Lobe ◽  
Before And After ◽  
Osmotic Reflection Coefficient

The osmotic reflection coefficient (sigma) can be estimated from the increases in hematocrit and plasma protein concentration that result from fluid filtration occurring in an isolated perfused organ. We determined what effect perfusion pump-induced hemolysis has on the value of sigma determined by this technique in both the isolated canine left lower lung lobe (LLL) and forelimb by comparing estimates of sigma obtained before and after correction for hemolysis. Hemolysis was corrected by using the slopes of the relationships between hematocrit and plasma hemoglobin concentration and between the plasma protein and hemoglobin concentrations to correct hematocrit and protein concentration to a state of zero hemolysis. Uncorrected estimates of sigma in the LLL were 1.19 +/- 0.14 (SE) at a venous pressure (Pv) of 12 Torr (n = 7) and 0.90 +/- 0.02 at a Pv of 19 Torr (n = 6). Both sets of LLL's yielded sigma values of 0.77 +/- 0.03 after hemolysis correction. In the forelimb (n = 5), uncorrected and corrected estimates of sigma of 0.99 +/- 0.03 and 0.85 +/- 0.01, respectively, were obtained. The latter values were similar to sigma's (0.88 +/- 0.01) determined by lymph analysis in five additional forelimbs. We conclude that hemolysis results in overestimates of sigma. After hemolysis correction, this technique yields similar results to those obtained from lymph analysis for the forelimb and from published values for the LLL.

Effect of luminal distension on intestinal transcapillary fluid exchange

1980 ◽  
Vol 239 (6) ◽  
pp. G516-G523
Author(s):  
D. N. Granger ◽  
P. R. Kvietys ◽  
N. A. Mortillaro ◽  
A. E. Taylor
Keyword(s):  
Blood Flow ◽  
Protein Concentration ◽  
Venous Pressure ◽  
Lymph Flow ◽  
Direct Effects ◽  
Fluid Exchange ◽  
Venous Outflow ◽  
Plasma Protein Concentration ◽  
Pressure Elevation ◽  
The Relationship

The direct effects of luminal distension pressure on intestinal transcapillary fluid exchange were studied in isolated autoperfused cat ileum preparations. Intestinal lymph flow, lymphatic pressure, lymph-to-plasma protein concentration ratio (L/P), blood flow, and perfusion pressures were allowed to reach a steady state at different luminal distension pressures (0–40 mmHg). Luminal distension was induced using a nonabsorbable silicone solution, thereby eliminating an influence of net water absorption. At a venous outflow pressure of 0 mmHg, lymph flow and lymphatic pressure increased, whereas blood flow and L/P decreased as luminal pressure was increased. The relationship between lymph flow, blood flow, and venous pressure was acquired at luminal pressures of 0 and 20 mmHg. When luminal pressure was 0, lymph flow increased and blood flow decreased progressively with venous pressure elevation; however, when luminal pressure was 20 mmHg, lymph flow and blood flow were unaffected until pressure exceeded 20 mmHg. The results of this study indicate that luminal pressure elevation enhances transcapillary fluid exchange and imposes a “waterfall” effect on the intestinal vasculature.

Permeability characteristics of colonic capillaries

1980 ◽  
Vol 239 (4) ◽  
pp. G300-G305 ◽  
Author(s):  
P. D. Richardson ◽  
D. N. Granger ◽  
D. Mailman ◽  
P. R. Kvietys
Keyword(s):  
Pressure Gradient ◽  
Plasma Protein ◽  
Protein Concentration ◽  
Venous Pressure ◽  
Molecular Size ◽  
Lymph Flow ◽  
Oncotic Pressure ◽  
Plasma Protein Concentration ◽  
Permeability Characteristics ◽  
Pressure Elevation

Blood flow, lymph flow, lymph protein concentration (CL), lymph oncotic pressure, plasma protein concentration (CP), and plasma oncotic pressure were determined under steady-state conditions at venous pressures of 0, 10, 20, 30, and 40 mmHg in autoperfused segments of dog colon. Venous pressure elevation increased colonic vascular resistance, lymph flow, lymphatic protein flux, and the transcapillary oncotic pressure gradient, whereas the lymph-to-plasma protein concentration ratio (CL/CP) declined. The osmotic reflection coefficient (sigma d) was estimated using sigma d = 1-CL/CP when CL/CP is filtration independent (high lymph flows). For total protein sigma d = 0.85 +/- 0.02. Values of sigma d for plasma protein fractions with molecular radii ranging between 37 and 120 A increased as molecular radius increased. The results of this study suggest that 1) colonic capillaries selectively restrict macromolecules on the basis of molecular size, and 2) an increased lymph flow and transcapillary oncotic pressure gradient may play an important role in preventing interstitial edema subsequent to venous pressure elevation in the dog colon.

Fluid uptake in the renal papilla by vasa recta estimated by two methods simultaneously

1985 ◽  
Vol 248 (3) ◽  
pp. F347-F353 ◽  
Author(s):  
B. Zimmerhackl ◽  
C. R. Robertson ◽  
R. L. Jamison
Keyword(s):  
Blood Flow ◽  
Plasma Protein ◽  
Protein Concentration ◽  
Conversion Function ◽  
Plasma Protein Concentration ◽  
Micropuncture Technique ◽  
Fluid Uptake ◽  
Vasa Recta ◽  
Capillary Fluid

Fluid uptake by vasa recta was determined by two independent methods, videomicroscopy and the micropuncture technique, in the exposed papilla of nine antidiuretic rats to reconcile differences in values previously obtained by the two techniques. Erythrocyte velocity (Vrbc) and diameter (D) in descending vasa recta (DVR) (n = 22) and ascending vasa recta (AVR) (n = 31) near the "base" of the papilla were measured. Using a conversion function determined in vitro, Vrbc was transformed into mean blood velocity (Vblood). From D and Vblood, mean blood flow (Q) in DVR and AVR was calculated. In DVR, mean Vrbc, D, and Q were 1.06 +/- 0.01 mm/s, 16.3 +/- 0.4 micron, and 10.6 +/- 1.4 nl/min, respectively. In AVR, each corresponding value differed significantly, 0.47 +/- 0.06 mm/s (P less than 0.001), 19.8 +/- 0.8 micron (P less than 0.001), and 5.65 +/- 1.3 nl/min (P less than 0.025), respectively. Blood samples from DVR and AVR were obtained by micropuncture from the same location. Plasma protein concentration (g/dl) was 5.1 +/- 0.6 in DVR, 4.0 +/- 0.4 (P less than 0.05) in AVR, and 3.6 +/- 0.3 (P less than 0.025) in the renal vein. Assuming no net transcapillary loss of protein, total plasma outflow exceeded inflow by 29%, the excess representing fluid uptake; and to reconcile the blood flow and plasma protein concentrations found, functioning AVR should outnumber functioning DVR by a ratio of 2.1-2.4 to 1, depending on local hematocrit. Given the total number of AVR + DVR = 2,944 (at the base), capillary fluid uptake was calculated to range between 1.5 and 2.6 microliter/min.

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