Changes in renal hemodynamics and renin release caused by increased plasma oncotic pressure

1976 ◽  
Vol 231 (5) ◽  
pp. 1550-1556 ◽  
Author(s):  
JE Hall ◽  
AC Guyton
Keyword(s):  
Renal Artery ◽  
Filtration Rate ◽  
Colloid Osmotic Pressure ◽  
Urine Flow ◽  
Renin Release ◽  
Sodium Pentobarbital ◽  
Oncotic Pressure ◽  
Electrolyte Excretion ◽  
Afferent Arterioles ◽  
Renal Responses

The effect of increased plasma oncotic pressure on renal blood flow (RBF), glomerular filtration rate (GFR), electrolyte excretion, and renin secretion rate (RSR) was studied in dogs anesthetized with sodium pentobarbital. Renal artery infusions of hyperoncotic dextran or human serum albumin raised renal venous colloid osmotic pressure an average of 7.3 and 10.1 mmHg, respectively, and caused small but consistent increases in RBF, large increases in RSR, marked decreases in urine flow rate and electrolyte excretion, with either no change or small decreases in GFR, and no change in renal artery pressure. Renal vasodilation was confined primarily to afferent arterioles and was not measureable until approximately 45 s after the start of infusions. The renal responses to increased plasma oncotic pressure appeared to be an autoregulatory phenomenon, consistent with a tubular mechanism dependent on an altered distal tubular fluid flow and/or composition. The increased renin release during increased plasma oncotic pressure is not compatible with a renal baroreceptor mechanism that responds to decreases in afferent arteriolar pressure because calculated glomerular pressure increased during albumin and dextran infusions.

Renal responses to graded hemorrhage in conscious pig

1990 ◽  
Vol 259 (1) ◽  
pp. R119-R125 ◽  
Author(s):  
J. L. Sondeen ◽  
G. A. Gonzaludo ◽  
J. A. Loveday ◽  
G. E. Deshon ◽  
C. B. Clifford ◽  
...  
Keyword(s):  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Arterial Pressure ◽  
Filtration Rate ◽  
Urine Flow ◽  
Electrolyte Excretion ◽  
Flow Probe ◽  
Ureteral Catheter ◽  
Time Points ◽  
Renal Responses

We developed a conscious pig model with a chronically instrumented kidney to measure renal blood flow (RBF), glomerular filtration rate (GFR), and excretory functions during hemorrhage. Seven to 10 days before experimentation, pigs were splenectomized, arterial and venous catheters were implanted, an ultrasonic flow probe was placed on the renal artery, and a pyelostomy was performed for nonocclusively placing a ureteral catheter. Measurements were taken before hemorrhage, and at hemorrhage volumes of 7, 14, 21, and 28 ml/kg (equivalent to 10.5, 21, 31, and 42% of the estimated blood volume), or at corresponding time points for controls. RBF was decreased by 30% when 21% of the blood (14 mg/kg) was removed, before arterial pressure, GFR, or urine flow or excretion was changed. At volumes of hemorrhage greater than 14 ml/kg, there were progressive decreases in RBF, GFR, urine flow rate, osmotic and electrolyte excretion, and arterial pressure. Thus pigs, like humans, respond to hypovolemia with an early redistribution of blood flow away from the kidney.

Renal and pressor action of angiotensin in the normal dog

1965 ◽  
Vol 208 (6) ◽  
pp. 1093-1099 ◽  
Author(s):  
John K. Healy ◽  
Carlos Barcena ◽  
J. M. Brian O'Connell ◽  
George E. Schreiner
Keyword(s):  
Filtration Rate ◽  
Pressor Response ◽  
Urine Flow ◽  
Sodium Reabsorption ◽  
Potassium Excretion ◽  
Control Blood Pressure ◽  
Electrolyte Excretion ◽  
Initial Depression ◽  
High Doses ◽  
Higher Doses

The renal and pressor actions of angiotensin in relation to dose were studied in unanesthetized dogs. Low doses caused depression of urine flow, electrolyte excretion, glomerular filtration rate (GFR), and Cpah. With higher doses, the initial depression of urine flow, GFR, and Cpah was greater, but subsequently these functions rose toward control values. In fact, diuresis occurred, accompanied by natriuresis, chloruresis, and kaliuresis. The natriuresis occurred at a time when GFR was significantly depressed. In longer experiments at high doses it was found that the natriuresis declined after 50 min despite continued angiotensin infusion; however, potassium excretion gradually increased throughout. These results help clarify the confusing literature regarding the effects of angiotensin on renal function in dogs and also support the hypothesis that angiotensin can block tubular sodium reabsorption. The pressor response was found to be proportional to the logarithm of the dose of angiotensin. It was also inversely related to the control blood pressure of the dog.

Renal actions of endothelin: interaction with prostacyclin

1990 ◽  
Vol 259 (4) ◽  
pp. F645-F652 ◽  
Author(s):  
S. Y. Chou ◽  
A. Dahhan ◽  
J. G. Porush
Keyword(s):  
Blood Pressure ◽  
Filtration Rate ◽  
Prostaglandin Synthesis ◽  
Urine Flow ◽  
Renin Release ◽  
Arterial Blood ◽  
Anesthetized Dogs ◽  
Inhibition Of Prostaglandin Synthesis ◽  
Arterial Plasma ◽  
Prostacyclin Synthesis

The renal actions of endothelin were examined by infusing it intrarenally in anesthetized dogs at 4 ng.min-1.kg-1 without affecting arterial blood pressure or cardiac output. Endothelin infusion caused a transient and significant increase in renal blood flow (RBF) by 13 +/- 2%, followed by large decreases in RBF and glomerular filtration rate (GFR; by 26 +/- 2 and 23 +/- 7%, respectively) but did not alter urine flow rate or absolute sodium excretion. After endothelin infusion, renal venous and arterial plasma 6-ketoprostaglandin F1 alpha increased from 250 +/- 58 and 117 +/- 31 to 1,044 +/- 249 and 617 +/- 211 pg/ml, respectively, and its renal output increased from 339 +/- 99 to 963 +/- 202 pg.min-1.g-1 (P less than 0.01 for all). The renal prostacyclin synthesis was augmented by endothelin without stimulating the renal renin release or norepinephrine output. Inhibition of prostaglandin synthesis with indomethacin partially prevented the early renal vasodilation induced by endothelin, which then caused a more pronounced decline in RBF and GFR (by 65 +/- 7 and 54 +/- 8%, respectively). With suppression of prostacyclin synthesis, inhibition of renin release by endothelin was observed. Thus the vasoconstrictive effects of endothelin on renal hemodynamics are significantly modified by its ability to enhance production of vasodilators, including prostacyclin.

Renal and vascular responses of the bullfrog (Rana catesbeiana) to mesotocin

1978 ◽  
Vol 235 (2) ◽  
pp. F151-F155 ◽  
Author(s):  
P. K. Pang ◽  
W. H. Sawyer
Keyword(s):  
Filtration Rate ◽  
Rana Catesbeiana ◽  
Urine Flow ◽  
Vascular Responses ◽  
Diuretic Agent ◽  
Diuretic Response ◽  
High Doses ◽  
Blood Pressure Responses ◽  
Renal Responses ◽  
Depressor Effect

Although mesotocin (MT) has long been known to occur in the amphibian neurohypophysis, there have been few reports on its action among amphibians. In the present investigation, renal responses of intact bullfrogs (Rana catesbeiana) and perfused bullfrog kidneys to MT were studied. The blood pressure responses of this amphibian to MT were also analyzed. We found that MT is diuretic at low doses and that the response is dose related. At high doses the diuretic response decreases progressively and, at times, antidiuresis is observed. The changes in urine flow are proportional to the changes in glomerular filtration rate. In addition, there is a dose-related depressor effect. Data from perfused kidney studies suggest that MT may dilate the afferent glomerular vessels. The possible action of MT as a physiologically important diuretic agent is discussed.

Hormonal, electrolyte, and renal responses to exercise are intensity dependent

1991 ◽  
Vol 70 (2) ◽  
pp. 900-906 ◽  
Author(s):  
B. J. Freund ◽  
E. M. Shizuru ◽  
G. M. Hashiro ◽  
J. R. Claybaugh
Keyword(s):  
Oxygen Consumption ◽  
Glomerular Filtration Rate ◽  
Atrial Natriuretic Peptide ◽  
Glomerular Filtration ◽  
Natriuretic Peptide ◽  
Filtration Rate ◽  
Maximal Oxygen Consumption ◽  
Work Load ◽  
Urine Flow ◽  
Renal Responses

Previous work indicates that the magnitude and direction of renal responses to exercise depend on the exercise intensity. To examine mechanisms responsible for these findings, renal and hormonal responses were studied in eight healthy male subjects (29.6 +/- 1.9 yr) before and immediately after four 20-min bouts of submaximal exercise (cycle ergometry) at work loads representing 25, 40, 60, and 80% of maximal oxygen consumption. Urine flow, osmotic clearance, glomerular filtration rate, and sodium excretion (UNa+V) all tended to rise at the 25% work load but were markedly reduced at the higher work intensities. Changes in urine flow paralleled changes in glomerular filtration rate (r = 0.91). Plasma vasopressin (ADH), aldosterone, and plasma renin activity tended to increase progressively with increases in work load, with the increases for all hormones reaching statistical significance when the level of exercise reached greater than or equal to 60% of maximal oxygen consumption. However, atrial natriuretic peptide was elevated (P less than 0.05) at all work loads from greater than 1.6-fold of control levels at the 25% work load to greater than 7-fold at the 80% work load. The increase in urine flow (6 of 8 subjects) and UNa+V (7 of 8 subjects) may be due to the increase in atrial natriuretic peptide and/or a 10% suppression (P less than 0.05) of ADH at the 25% work load.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of acetylcholine on urinary electrolyte excretion

1964 ◽  
Vol 207 (5) ◽  
pp. 979-982 ◽  
Author(s):  
G. G. Pinter ◽  
C. C. C. O'morchoe ◽  
R. S. Sikand
Keyword(s):  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Urine Flow ◽  
Electrolyte Excretion ◽  
Renal Effects ◽  
Medullary Blood Flow ◽  
Important Mediator ◽  
Separate Control ◽  
Consistent Change ◽  
Excretion Rates

Acetylcholine was infused into the aorta of unanesthetized dogs above the origin of the renal arteries. It produced a statistically significant increase in Na, Cl, and K excretion rates and in renal plasma flow with respect to control values in the same experiments and to results obtained in separate control experiments on the same animals. No consistent change was found in glomerular filtration rate, urine flow, and osmolality. In similar experiments Pitressin was also infused. The renal effects of acetylcholine were slightly enhanced by Pitressin. It was concluded that the antidiuretic hormone was not an important mediator in the production of renal effects during acetylcholine infusion. The possible roles of increased medullary blood flow and of increased angiotensin production are discussed.

Role of renal dopamine D1 receptors in natriuresis induced by calcium channel blockers

1994 ◽  
Vol 267 (6) ◽  
pp. F965-F970
Author(s):  
G. M. Eisner ◽  
I. Yamaguchi ◽  
R. A. Felder ◽  
L. D. Asico ◽  
P. A. Jose
Keyword(s):  
Glomerular Filtration Rate ◽  
Renal Artery ◽  
Calcium Channel ◽  
Glomerular Filtration ◽  
Calcium Channel Blockers ◽  
Sodium Excretion ◽  
Filtration Rate ◽  
Urine Flow ◽  
Channel Blockers ◽  
The Right

The direct tubular natriuretic effect of calcium channel blockers (CCBs) may be due to an interaction between CCBs and a renal tubular dopamine receptor. We therefore studied the effects of two chemically unrelated CCBs, diltiazem and isradipine, infused into the right renal artery of 5% saline-loaded anesthetized rats alone or in the presence of a D1 antagonist, SKF-83742. Isradipine (0.03 microgram.kg-1.min-1) or diltiazem (20 but not 10 micrograms.kg-1.min-1) alone produced an increase in urine flow and an approximate doubling of absolute and fractional sodium excretion, which was not seen in the left kidney or in the control animals (analysis of variance, Scheffe's test, P < 0.05). SKF-83742 alone given systemically or into the right renal artery did not affect these parameters but did block the actions of diltiazem or isradipine. There was no change in mean arterial pressure, renal blood flow, or glomerular filtration rate in any of the experiments. In additional studies, we found that a combined infusion of dopamine (0.1 microgram.kg-1.min-1) and diltiazem (10 micrograms.kg-1.min-1) (doses that by themselves did not alter renal function) produced a twofold or greater increase in urine flow and absolute and fractional sodium excretion; glomerular filtration rate was not significantly changed. Intrarenal arterial CCBs, without a change in renal hemodynamics, produce a natriuresis that is blocked by a D1 antagonist. Concomitant administration of diltiazem and dopamine (each in subeffective doses when used alone) produces a synergistic effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Relative roles of glomerular filtration and tubular reabsorption in denervation diuresis

1962 ◽  
Vol 202 (4) ◽  
pp. 777-780 ◽  
Author(s):  
William D. Blake
Keyword(s):  
Glomerular Filtration ◽  
Filtration Rate ◽  
Tubular Reabsorption ◽  
Urine Flow ◽  
Electrolyte Excretion ◽  
Reabsorptive Capacity ◽  
Standard Procedures ◽  
Total Filtration ◽  
Proximal Tubular ◽  
Solute Excretion

Experiments have been carried out on anesthetized, laparotomized dogs in which urine samples were collected from both kidneys after acute denervation of one. Renal functions were estimated by standard procedures with creatinine clearance (CCr) as an index of glomerular filtration rate. Urine flow and solute excretion were greater from the denervated kidney (D) than from the innervated kidney (I) under all conditions of solute diuresis. The magnitude of denervation diuresis, D/I for urine flow, was directly related to the relative excess of electrolyte excretion on the denervated side, D/I for electrolyte excretion rate. D/I for electrolyte excretion was not correlated with D/I for CCr and remained above 100% in all experiments despite a fall of D/I for CCr below 100% in 10 of 30 comparisons. Since excessive electrolyte excretion by the denervated kidney could not be explained by greater total filtration rate, it was reaffirmed that denervation caused a defect in proximal tubular reabsorption of sodium, either by decreased reabsorptive activity of all tubules or by redistribution of filtration toward tubules of lesser reabsorptive capacity.

Effects of Moxibusting Point Kuan-Yuan on Cardiovascular and Renal Responses to Histamine-Induced Shock

1987 ◽  
Vol 15 (01n02) ◽  
pp. 77-82 ◽  
Author(s):  
Ho-Chan Chen ◽  
Gunilla Brattberg
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Sympathetic Activity ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Chinese Herb ◽  
Peripheral Resistance ◽  
Urine Flow ◽  
Anesthetized Dogs ◽  
Renal Responses

Moxibustion of the Point Kuan-Yuan is said by some Chinese herb doctors to have "anti-shock" effect. Using histamine-induced shock in anesthetized dogs, we studied the cardiovascular and renal effects of moxibusting Point Kuan-Yuan. We found that it significantly increased cardiac output, total peripheral resistance, and mean blood pressure but it did not significantly increase heart rate. Moxibustion also significantly increased renal plasma flow, golmerular filtration rate, urine flow, and Na+ Cl–K+ excretions. Whether moxibusting Kuan-Yuan may be useful as an adjunct in treating clinical shocks deserves more extensive studies in well-controlled situations. It may be helpful in clinical situations in which elevation of the sympathetic activity may be beneficial.

The Patterns of Renal Electrolyte Excretion in the Duck (Anas Platyrhynchos) Maintained on Freshwater and on Hypertonic Saline

1968 ◽  
Vol 48 (3) ◽  
pp. 487-508
Author(s):  
W. N. HOLMES ◽  
G. L. FLETCHER ◽  
D. J. STEWART
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Hypertonic Saline ◽  
Plasma Flow ◽  
Inorganic Phosphate ◽  
Filtration Rate ◽  
Renal Excretion ◽  
Renal Plasma Flow ◽  
Urine Flow ◽  
Electrolyte Excretion

1. The renal excretion of water and electrolytes was examined in starved ducks maintained on fresh water and on hypertonic saline containing 284 mM/1. NaCl and 6.0 mM/l. KCl. 2. No significant differences were observed in the urine flow, glomerular filtration rate, renal plasma flow and the excretory rates of K+, NH4+ and inorganic phosphate between these two groups of birds. 3. The excretory rates of Na+, Cl- and Ca2+ were significantly higher in saline-maintained birds than in the freshwater-maintained birds. 4. NH4+ appeared to be a major cationic component which occupied over half of the available osmotic space in the urine of both the freshwater-maintained and saline-maintained birds. 5. In saline-maintained birds the excretion of K+ and inorganic phosphate appeared to be independent of the available osmotic space in the urine whereas the excretion of Na+ and Cl- appeared to be very dependent upon this factor. 6. These observations suggest that the kidneys of the saline-maintained bird constitute the primary pathway for the excretion of K+, NH4+ and inorganic phosphate, and that with respect to the excretion of Na+ they constitute a relatively minor pathway.

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