Effect of General Anaesthesia on Renal Haemodynamics in the Rat

1979 ◽  
Vol 57 (5) ◽  
pp. 469-471 ◽  
Author(s):  
B. M. Koeppen ◽  
A. I. Katz ◽  
M. D. Lindheimer
Keyword(s):  
Blood Flow ◽  
Renal Function ◽  
Renal Blood Flow ◽  
General Anaesthesia ◽  
Renal Haemodynamics ◽  
Sodium Pentobarbital ◽  
Radioactive Microspheres ◽  
Anaesthetic Agents ◽  
Total Renal Blood Flow

1. The effect of sodium pentobarbital and Inactin anaesthesia on renal haemodynamics in the rat was evaluated with radioactive microspheres 15 μm in diameter. 2. Both anaesthetic agents caused substantial decrements in total renal blood flow (sodium pentobarbital, −34%; Inactin, −24%) compared with unanaesthetized animals. 3. Measurements of renal function obtained in rats anaesthetized with either of these anaesthetic agents should be interpreted with caution.

Measurement of Intrarenal Blood-Flow Distribution in the Rabbit Using Radioactive Microspheres

1975 ◽  
Vol 48 (1) ◽  
pp. 51-60 ◽  
Author(s):  
D. J. Warren ◽  
J. G. G. Ledingham
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Renal Cortex ◽  
Flow Distribution ◽  
Rabbit Kidney ◽  
Radioactive Microspheres ◽  
Injection Dose ◽  
Intrarenal Blood Flow ◽  
Total Renal Blood Flow

1. Total renal blood flow and its distribution within the renal cortex of the conscious rabbit were studied with radioactive microspheres of 15 and 25 μm diameter. 2. The reliability of the microsphere technique was influenced by microsphere diameter and number (dose). The optimum microsphere diameter for determination of flow distribution in the rabbit kidney was 15 μm and dose 100–150 000 spheres. 3. Spheres of 15 μm nominal diameter were randomly distributed within the renal cortex of adult rabbits. The larger spheres in batches nominally 15 μm in diameter in young rabbits and 25 μm diameter in adult rabbits were preferentially distributed to the superficial cortex. 4. In adult rabbits 15 μm diameter spheres lodged in glomerular capillaries. Larger spheres occasionally lodged in interlobular arteries causing intrarenal haemorrhage. 5. Microspheres of 15 μm caused a decrease in renal clearance of creatinine and of p-aminohippurate when the total injection dose was about 200 000 spheres. These effects were greater when the injection dose was increased to 500 000 spheres. 6. The reduction in total renal blood flow observed with large doses of spheres largely reflected decreased outer cortical flow, as measured by a second injection of spheres, and confirmed by a decrease in p-aminohippurate extraction. 7. The reproducibility of multiple injection studies was limited by these intrarenal effects of microspheres. 8. Total renal blood flow measured in six rabbits in acute experiments by the microsphere technique was 107 ± 12 (mean±sd) ml/min and by p-aminohippurate clearance was 100 ± 10 ml/min. 9. Total renal blood flow in twelve conscious, chronically instrumented rabbits was 125 ± 11 ml/min, of which 92 ± 6 ml/min was distributed to the superficial cortex and 33 ± 4 ml/min to the deep cortex.

Pressure-flow studies in the isolated artificial heart-lung perfused mammalian kidney

1960 ◽  
Vol 199 (3) ◽  
pp. 499-502 ◽  
Author(s):  
Sheldon Rosenfeld ◽  
Alvin L. Sellers
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Renal Function ◽  
Renal Blood Flow ◽  
Whole Blood ◽  
Artificial Heart ◽  
Spinal Cord Transection ◽  
Rabbit Kidney ◽  
Sodium Pentobarbital ◽  
Kidney Donor

This study attempts to define some of the physiologic characteristics of the isolated whole blood artificial heart-lung perfused rabbit kidney and describes a modification of an original method previously described. The effects of anesthesia of the kidney donor animal with intraperitoneal ethyl alcohol, intravenous sodium pentobarbital and cervical spinal cord transection (performed on unanesthetized animals) have been compared in terms of renal function and the relationship of renal blood flow to changing perfusion pressures. When spinal cord transection was used, relatively normal levels of renal function were obtained in better than 90% of the experiments. Average values for 12 experiments are: observed renal plasma flow = 1.70; creatinine and p-aminohippuric acid (PAH) clearance = .28 and 1.3 ml/min/gm kidney weight; PAH extraction = 75%; and U:P ratios for creatinine and glucose = 26:1 and 0.1:1. Autoregulation of renal blood flow was demonstrated in a completely denervated kidney perfused with whole blood but was abolished when alcohol anesthesia was used in the kidney donor rabbit. There appeared to be no correlation between the presence or absence of this phenomenon and the level of clearance function achieved by the kidney.

Renal Circulatory Responses to General Anaesthesia in the Rabbit: Studies Using Radioactive Microspheres

1975 ◽  
Vol 48 (1) ◽  
pp. 61-66 ◽  
Author(s):  
D. J. Warren ◽  
J. G. G. Ledingham
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Sodium Excretion ◽  
Urinary Sodium Excretion ◽  
Control Mechanisms ◽  
Anaesthetic Agents ◽  
Regional Renal Blood Flow ◽  
Urethane Anaesthesia ◽  
Cortical Distribution ◽  
Total Renal Blood Flow

1. Total renal blood flow and its cortical distribution were measured by the radioactive microsphere technique in conscious rabbits and after anaesthesia with pentobarbitone, chloralose-urethane or ether. 2. Pentobarbitone anaesthesia caused a fall of 26% in total renal blood flow, of 26% in superficial cortical flow, and of 24% in deep cortical flow. Sodium excretion rate fell by 33%. 3. Chloralose-urethane anaesthesia caused no change in total or regional renal blood flow, or in sodium excretion. 4. Ether anaesthesia caused an insignificant fall in total renal blood flow, but superficial cortical flow fell by 13 % and deep cortical flow rose by 21 %. Urinary sodium excretion fell by 65%. 5. Possible mechanisms for these changes in response to anaesthesia are discussed. 6. The effects of anaesthetic agents may influence the interpretation of published work on control mechanisms in the renal circulation.

Effects of l-arginine on systemic and renal haemodynamics in conscious dogs

1991 ◽  
Vol 81 (6) ◽  
pp. 727-732 ◽  
Author(s):  
Marohito Murakami ◽  
Hiromichi Suzuki ◽  
Atsuhiro Ichihara ◽  
Mareo Naitoh ◽  
Hidetomo Nakamoto ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Renal Blood Flow ◽  
Arterial Blood Pressure ◽  
Mean Arterial Blood Pressure ◽  
Renal Haemodynamics ◽  
Conscious Dogs ◽  
Arginine Infusion ◽  
Arterial Blood

1. The effects of l-arginine on systemic and renal haemodynamics were investigated in conscious dogs. l-Arginine was administered intravenously at doses of 15 and 75 μmol min−1 kg−1 for 20 min. 2. Mean arterial blood pressure, heart rate and cardiac output were not changed significantly by l-arginine infusion. However, l-arginine infusion induced a significant elevation of renal blood flow from 50 ± 3 to 94 ± 12 ml/min (means ± sem, P < 0.01). 3. Simultaneous infusion of NG-monomethyl-l-arginine (0.5 μmol min−1 kg−1) significantly inhibited the increase in renal blood flow produced by l-arginine (15 μmol min−1 kg−1) without significant changes in mean arterial blood pressure or heart rate. 4. Pretreatment with atropine completely inhibited the l-arginine-induced increase in renal blood flow, whereas pretreatment with indomethacin attenuated it (63 ± 4 versus 82 ± 10 ml/min, P < 0.05). 5. A continuous infusion of l-arginine increased renal blood flow in the intact kidney (55 ± 3 versus 85 ± 9 ml/min, P < 0.05), but not in the contralateral denervated kidney (58 ± 3 versus 56 ± 4 ml/min, P > 0.05). 6. These results suggest that intravenously administered l-arginine produces an elevation of renal blood flow, which may be mediated by facilitation of endogenous acetylcholine-induced release of endothelium-derived relaxing factor and vasodilatory prostaglandins.

Aortic blood flow subtraction: an alternative method for measuring total renal blood flow in conscious dogs

2002 ◽  
Vol 282 (5) ◽  
pp. R1528-R1535 ◽  
Author(s):  
N. C. F. Sandgaard ◽  
J. L. Andersen ◽  
N.-H. Holstein-Rathlou ◽  
P. Bie
Keyword(s):  
Blood Flow ◽  
Angiotensin Ii ◽  
Renal Blood Flow ◽  
Aortic Blood Flow ◽  
Excretory Function ◽  
Endothelin 1 ◽  
Arterial Blood ◽  
Aortic Blood ◽  
Bilateral Carotid ◽  
Total Renal Blood Flow

We have measured total renal blood flow (TRBF) as the difference between signals from ultrasound flow probes implanted around the aorta above and below the renal arteries. The repeatability of the method was investigated by repeated, continuous infusions of angiotensin II and endothelin-1 seven times over 8 wk in the same dog. Angiotensin II decreased TRBF (350 ± 16 to 299 ± 15 ml/min), an effect completely blocked by candesartan (TRBF 377 ± 17 ml/min). Subsequent endothelin-1 infusion reduced TRBF to 268 ± 20 ml/min. Bilateral carotid occlusion (8 sessions in 3 dogs) increased arterial blood pressure by 49% and decreased TRBF by 12%, providing an increase in renal vascular resistance of 69%. Dynamic analysis showed autoregulation of renal blood flow in the frequency range <0.06–0.07 Hz, with a peak in the transfer function at 0.03 Hz. It is concluded that continuous measurement of TRBF by aortic blood flow subtraction is a practical and reliable method that allows direct comparison of excretory function and renal blood flow from two kidneys. The method also allows direct comparison between TRBF and flow in the caudal aorta.

Role of the renal medulla in volume and arterial pressure regulation

1997 ◽  
Vol 273 (1) ◽  
pp. R1-R15 ◽  
Author(s):  
A. W. Cowley
Keyword(s):  
Blood Flow ◽  
Arterial Pressure ◽  
Renal Blood Flow ◽  
Fluid Pressure ◽  
Regulatory System ◽  
Renal Medulla ◽  
Water Excretion ◽  
Vasa Recta ◽  
Pressure Natriuresis ◽  
Total Renal Blood Flow

The original fascination with the medullary circulation of the kidney was driven by the unique structure of vasa recta capillary circulation, which Berliner and colleagues (Berliner, R. W., N. G. Levinsky, D. G. Davidson, and M. Eden. Am. J. Med. 24: 730-744, 1958) demonstrated could provide the economy of countercurrent exchange to concentrate large volumes of blood filtrate and produce small volumes of concentrated urine. We now believe we have found another equally important function of the renal medullary circulation. The data show that it is indeed the forces defined by Starling 100 years ago that are responsible for the pressure-natriuresis mechanisms through the transmission of changes of renal perfusion pressure to the vasa recta circulation. Despite receiving only 5-10% of the total renal blood flow, increases of blood flow to this region of the kidney cause a washout of the medullary urea gradient and a rise of the renal interstitial fluid pressure. These forces reduce tubular reabsorption of sodium and water, leading to a natriuresis and diuresis. Many of Starling's intrinsic chemicals, which he named "hormones," importantly modulate this pressure-natriuresis response by altering both the sensitivity and range of arterial pressure around which these responses occur. The vasculature of the renal medulla is uniquely sensitive to many of these vasoactive agents. Finally, we have found that the renal medullary circulation can play an important role in determining the level of arterial pressure required to achieve long-term fluid and electrolyte homeostasis by establishing the slope and set point of the pressure-natriuresis relationship. Measurable decreases of blood flow to the renal medulla with imperceptible changes of total renal blood flow can lead to the development of hypertension. Many questions remain, and it is now evident that this is a very complex regulatory system. It appears, however, that the medullary blood flow is a potent determinant of both sodium and water excretion and signals changes in blood volume and arterial pressure to the tubules via the physical forces that Professor Starling so clearly defined 100 years ago.

Oestrogen-induced changes in renal haemodynamics in the rat: Influence of plasma and intrarenal renin

1986 ◽  
Vol 71 (5) ◽  
pp. 613-619 ◽  
Author(s):  
Mr J. K. Evans ◽  
P. F. Naish ◽  
G. M. Aber
Keyword(s):  
Blood Flow ◽  
Plasma Renin Activity ◽  
Renal Blood Flow ◽  
Vascular Resistance ◽  
Peripheral Resistance ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Renal Haemodynamics ◽  
Renin Activity ◽  
Female Rats

1. The effect of oestrone acetate (in total doses of 5 and 10 mg) on systemic and renal haemodynamics and the renin-angiotensin system has been studied in adult female rats. 2. The administration of 10 mg of oestrogen resulted in a significant fall in renal blood flow associated with significant rises in both renal vascular resistance and mean arterial pressure. No changes were noted in cardiac output or total peripheral resistance at either dose. 3. Whilst the higher dose of oestrogen induced a significant increase in plasma renin activity, no change was noted in animals receiving 5 mg of oestrogen. Both regimens caused significant reductions in plasma and intrarenal renin concentrations. 4. Although renal blood flow correlated with plasma renin activity in animals with a normal renal blood flow, no such correlation was noted in animals with oestrogen-induced reductions in renal blood flow. 5. The present study demonstrates that oestrogen-induced reductions in renal blood flow result from a rise in intrarenal vascular resistance which cannot be accounted for by simultaneous changes in either plasma renin activity or renal renin concentration.

scholarly journals Global REACH 2018: renal oxygen delivery is maintained during early acclimatization to 4,330 m

2020 ◽  
Vol 319 (6) ◽  
pp. F1081-F1089
Author(s):  
Andrew R. Steele ◽  
Michael M. Tymko ◽  
Victoria L. Meah ◽  
Lydia L. Simpson ◽  
Christopher Gasho ◽  
...  
Keyword(s):  
Blood Flow ◽  
Renal Function ◽  
High Altitude ◽  
Renal Blood Flow ◽  
Sea Level ◽  
Oxygen Delivery ◽  
Acid Base ◽  
Altitude Acclimatization ◽  
High Altitude Acclimatization ◽  
Renal Oxygen

Early acclimatization to high altitude is characterized by various respiratory, hematological, and cardiovascular adaptations that serve to restore oxygen delivery to tissue. However, less is understood about renal function and the role of renal oxygen delivery (RDO2) during high altitude acclimatization. We hypothesized that 1) RDO2 would be reduced after 12 h of high altitude exposure (high altitude day 1) but restored to sea level values after 1 wk (high altitude day 7) and 2) RDO2 would be associated with renal reactivity, an index of acid-base compensation at high altitude. Twenty-four healthy lowlander participants were tested at sea level (344 m, Kelowna, BC, Canada) and on day 1 and day 7 at high altitude (4,330 m, Cerro de Pasco, Peru). Cardiac output, renal blood flow, and arterial and venous blood sampling for renin-angiotensin-aldosterone system hormones and NH2-terminal pro-B-type natriuretic peptides were collected at each time point. Renal reactivity was calculated as follows: (Δarterial bicarbonate)/(Δarterial Pco2) between sea level and high altitude day 1 and sea level and high altitude day 7. The main findings were that 1) RDO2 was initially decreased at high altitude compared with sea level (ΔRDO2: −22 ± 17%, P < 0.001) but was restored to sea level values on high altitude day 7 (ΔRDO2: −6 ± 14%, P = 0.36). The observed improvements in RDO2 resulted from both changes in renal blood flow (Δ from high altitude day 1: +12 ± 11%, P = 0.008) and arterial oxygen content (Δ from high altitude day 1: +44.8 ± 17.7%, P = 0.006) and 2) renal reactivity was positively correlated with RDO2 on high altitude day 7 ( r = 0.70, P < 0.001) but not high altitude day 1 ( r = 0.26, P = 0.29). These findings characterize the temporal responses of renal function during early high altitude acclimatization and the influence of RDO2 in the regulation of acid-base balance.

scholarly journals Downstream effects of splanchnic ischemia-reperfusion injury on renal function and eicosanoid release

1997 ◽  
Vol 83 (2) ◽  
pp. 530-536 ◽  
Author(s):  
Patricia Rothenbach ◽  
Richard H. Turnage ◽  
Jose Iglesias ◽  
Angela Riva ◽  
Lori Bartula ◽  
...  
Keyword(s):  
Blood Flow ◽  
Renal Function ◽  
Reperfusion Injury ◽  
Renal Blood Flow ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Inulin Clearance ◽  
Downstream Effects ◽  
Splanchnic Ischemia ◽  
Eicosanoid Release

Rothenbach, Patricia, Richard H. Turnage, Jose Iglesias, Angela Riva, Lori Bartula, and Stuart I. Myers. Downstream effects of splanchnic ischemia-reperfusion injury on renal function and eicosanoid release. J. Appl. Physiol.82(2): 530–536, 1997.—This study examines the hypothesis that intestinal ischemia-reperfusion (I/R) injury contributes to renal dysfunction by altered renal eicosanoid release. Anesthetized Sprague-Dawley rats underwent 60 min of sham or superior mesenteric artery (SMA) occlusion with 60 min of reperfusion. The I/R groups received either allopurinol, pentoxifylline, 1-benzylimidazole, or carrier before SMA occlusion. In vivo renal artery blood flow was measured by Transonic flow probes, the kidneys were then perfused in vitro for 30 min, and the effluent was analyzed for eicosanoid release and renal function. Intestinal I/R caused a twofold increase in the ratio of renal release of thromboxane B2to prostaglandin E2and to 6-ketoprostaglandin F1αcompared with the sham level, with a corresponding 25% decrease in renal sodium and inulin clearance and renal blood flow. Pentoxifylline or allopurinol pretreatment restored renal eicosanoid release and renal sodium and inulin clearance to the sham level but did not alter renal blood flow. Pretreatment with 1-benzylimidazole restored renal function, eicosanoid release, and renal blood flow to sham levels. These data suggest that severe intestinal I/R contributes to the downregulation of renal function. The decrease in renal function is due in part to toxic oxygen metabolites, which occur in the milieu of altered renal eicosanoid release, reflecting a decrease in vasodilator and an increase in vasoconstrictor eicosanoids.

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