scholarly journals Blood perfusion of the kidney of Lophius piscatorius L.

1955 ◽  
Vol 34 (2) ◽  
pp. 217-222 ◽  
Author(s):  
L. Brull ◽  
Y. Cuypers ◽  
L. Wilsens
Keyword(s):  
Blood Flow ◽  
Blood Perfusion ◽  
Urine Flow ◽  
High Tension ◽  
Aerobic Processes ◽  
Water Secretion

SUMMARYKidneys of Lophius piscatorius L., perfused with heparinized blood, respond to a high tension of CO2 in the blood by a drop in urine flow and in their capacity for concentrating Mg. At the same time, but independently, CO2 reduces the blood flow. Both cyanide and fluoride may stop or reduce water secretion and Mg concentration, according to the concentration used, showing that both these activities are dependent on aerobic processes and presumably on the integrity of the carbohydrate cycle.

scholarly journals Blood perfusion of the kidney of Lophius piscatorius L.: II. Influence of perfusion pressure on urine volume

1954 ◽  
Vol 33 (3) ◽  
pp. 733-738 ◽  
Author(s):  
L. Brull ◽  
Y. Cuypers
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Critical Level ◽  
Perfusion Pressure ◽  
Urine Volume ◽  
Blood Perfusion ◽  
Urine Flow ◽  
Active Process ◽  
Flow Through ◽  
Water Secretion

SummaryThe urine secretion of the kidneys of Lophius piscatorius perfused with heparinized Lophius blood is very sensitive to perfusion pressure below a critical level, above which it becomes insensitive. The response of the urine flow to pressure takes the form of an exponential curve.The blood flow through the kidneys, while rising slowly at pressures of about 20–30 mm of water, responds arithmetically to pressure above such levels.At present it is impossible to make out whether pressure or blood flow has the greatest influence on secretion.Water secretion in the aglomerular kidney is an active process. The oxygen consumption of the Lophius kidney is unmeasurably low, yet remains a possible factor in secretion.

scholarly journals Blood Perfusion of the Kidney of Lophius Piscatorius L.

1953 ◽  
Vol 32 (2) ◽  
pp. 329-336 ◽  
Author(s):  
L. Brull ◽  
E. Nizet ◽  
E. B. Verney
Keyword(s):  
Blood Flow ◽  
Critical Level ◽  
Perfusion Pressure ◽  
Blood Perfusion ◽  
Urine Flow ◽  
The Other ◽  
Protein Nitrogen ◽  
Other Hand ◽  
Flow Through

Lophius kidneys perfused with the heparinized blood (venous) of the fish secrete urine in which total non-protein nitrogen is concentrated, magnesium highly concentrated, and chloride only slightly so or not at all. Oxygenation of the blood, or lowering the temperature of the perfusate from c. 20° to c. 5° C. does not appear to influence secretion. The blood flow through the kidneys increases with the perfusion pressure, the increase often becoming disproportionately large. The urine flow, on the other hand, above a certain critical level is largely independent of changes in perfusion pressure.

scholarly journals Diagnosis of Fibrotic Distal Ileum Stenosis after Ischemic Enteritis Using Transabdominal Ultrasonography

2021 ◽  
pp. 568-577
Author(s):  
Ryo Katsumata ◽  
Noriaki Manabe ◽  
Masaki Matsubara ◽  
Jun Nakamura ◽  
Kazuma Kawahito ◽  
...  
Keyword(s):  
Blood Flow ◽  
Case Reports ◽  
Blood Perfusion ◽  
Distal Ileum ◽  
Wall Thickening ◽  
Current Case ◽  
Abdominal Ultrasonography ◽  
Transabdominal Ultrasonography ◽  
Stenotic Lesion ◽  
Ischemic Enteritis

Ischemic enteritis (IE) is a rare disorder which is caused by inadequate blood flow to small intestine. The diagnostic procedure of this disease has not sufficiently established because of its rarity. Here, we report a case of IE in a hemodialysis-dependent 70-year-old man and summarize the diagnostic options for IE. The patient was admitted to our hospital because of acute abdominal distention and vomiting. He presented with mild tenderness in the lower abdomen and slightly elevated C-reactive protein level as revealed by blood tests. Radiographic imaging showed small bowel obstruction due to a stricture in the distal ileum. Contrast-enhanced abdominal ultrasonography revealed a 7-cm stenotic site with increased intestinal wall thickening, which preserved mucosal blood perfusion. Elastography revealed a highly elastic alteration of the stenotic lesion, indicating benign fibrotic changes resulting from chronic insufficient blood flow. Based on a clinical diagnosis of IE with fibrous stenosis, a partial ileostomy was performed. After surgical treatment, oral intake was initiated without recurrence of intestinal obstruction. Pathological findings revealed deep ulceration with inflammatory cell infiltration at the stenotic site. Occlusion and hyalinization of the venules in the submucosal layer indicated IE. In addition to current case, we reviewed past case reports of IE. Through this case presentation and literature review, we summarize the usefulness and safety of transabdominal ultrasonography for diagnosing IE.

Renal blood flow, early distal sodium, and plasma renin concentrations during osmotic diuresis

2000 ◽  
Vol 279 (4) ◽  
pp. R1268-R1276 ◽  
Author(s):  
Paul P. Leyssac ◽  
Niels-Henrik Holstein-Rathlou ◽  
Ole Skøtt
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Sodium Excretion ◽  
Plasma Renin ◽  
Urine Flow ◽  
Sodium Reabsorption ◽  
Osmotic Diuresis ◽  
Nacl Concentration ◽  
Proximal Tubular ◽  
Distal Tubules

Inconsistencies in previous reports regarding changes in early distal NaCl concentration (EDNaCl) and renin secretion during osmotic diuresis motivated our reinvestigation. After intravenous infusion of 10% mannitol, EDNaCl fell from 42.6 to 34.2 mM. Proximal tubular pressure increased by 12.6 mmHg. Urine flow increased 10-fold, and sodium excretion increased by 177%. Plasma renin concentration (PRC) increased by 58%. Renal blood flow and glomerular filtration rate decreased, however end-proximal flow remained unchanged. After a similar volume of hypotonic glucose (152 mM), EDNaClincreased by 3.6 mM, ( P < 0.01) without changes in renal hemodynamics, urine flow, sodium excretion rate, or PRC. Infusion of 300 μmol NaCl in a smaller volume caused EDNaCl to increase by 6.4 mM without significant changes in PRC. Urine flow and sodium excretion increased significantly. There was a significant inverse relationship between superficial nephron EDNaCl and PRC. We conclude that EDNa decreases during osmotic diuresis, suggesting that the increase in PRC was mediated by the macula densa. The results suggest that the natriuresis during osmotic diuresis is a result of impaired sodium reabsorption in distal tubules and collecting ducts.

Role of renal medullary adenosine in the control of blood flow and sodium excretion

1999 ◽  
Vol 276 (3) ◽  
pp. R790-R798 ◽  
Author(s):  
Ai-Ping Zou ◽  
Kasem Nithipatikom ◽  
Pin-Lan Li ◽  
Allen W. Cowley
Keyword(s):  
Blood Flow ◽  
Sodium Excretion ◽  
Renal Medulla ◽  
Urine Flow ◽  
Doppler Flowmetry ◽  
Blood Flows ◽  
Medullary Blood Flow ◽  
Adenosine Concentration ◽  
Interstitial Infusion

This study determined the levels of adenosine in the renal medullary interstitium using microdialysis and fluorescence HPLC techniques and examined the role of endogenous adenosine in the control of medullary blood flow and sodium excretion by infusing the specific adenosine receptor antagonists or agonists into the renal medulla of anesthetized Sprague-Dawley rats. Renal cortical and medullary blood flows were measured using laser-Doppler flowmetry. Analysis of microdialyzed samples showed that the adenosine concentration in the renal medullary interstitial dialysate averaged 212 ± 5.2 nM, which was significantly higher than 55.6 ± 5.3 nM in the renal cortex ( n = 9). Renal medullary interstitial infusion of a selective A1antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; 300 pmol ⋅ kg−1 ⋅ min−1, n = 8), did not alter renal blood flows, but increased urine flow by 37% and sodium excretion by 42%. In contrast, renal medullary infusion of the selective A2 receptor blocker 3,7-dimethyl-1-propargylxanthine (DMPX; 150 pmol ⋅ kg−1 ⋅ min−1, n = 9) decreased outer medullary blood flow (OMBF) by 28%, inner medullary blood flows (IMBF) by 21%, and sodium excretion by 35%. Renal medullary interstitial infusion of adenosine produced a dose-dependent increase in OMBF, IMBF, urine flow, and sodium excretion at doses from 3 to 300 pmol ⋅ kg−1 ⋅ min−1( n = 7). These effects of adenosine were markedly attenuated by the pretreatment of DMPX, but unaltered by DPCPX. Infusion of a selective A3receptor agonist, N 6-benzyl-5′-( N-ethylcarbonxamido)adenosine (300 pmol ⋅ kg−1 ⋅ min−1, n = 6) into the renal medulla had no effect on medullary blood flows or renal function. Glomerular filtration rate and arterial pressure were not changed by medullary infusion of any drugs. Our results indicate that endogenous medullary adenosine at physiological concentrations serves to dilate medullary vessels via A2 receptors, resulting in a natriuretic response that overrides the tubular A1 receptor-mediated antinatriuretic effects.

Inhibition of nitric oxide synthesis attenuates pressure-induced natriuretic responses in anesthetized dogs

1993 ◽  
Vol 264 (1) ◽  
pp. F79-F87 ◽  
Author(s):  
D. S. Majid ◽  
A. Williams ◽  
L. G. Navar
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Sodium Excretion ◽  
Renin Angiotensin System ◽  
Fractional Excretion ◽  
Urine Flow ◽  
Synthesis Inhibition ◽  
Fractional Excretion Of Sodium ◽  
Anesthetized Dogs ◽  
Pressure Natriuresis

Inhibition of nitric oxide (NO) synthesis by intrarenal administration of nitro-L-arginine (NLA) leads to decreases in urinary sodium excretion (UNaV) in association with the increases in renal vascular resistance (RVR). In the present study, we examined the ability of the kidney to alter its sodium excretion in response to acute changes in renal arterial pressure (RAP) in anesthetized dogs before and during intrarenal infusion of NLA (50 micrograms.kg-1.min-1). NO synthesis inhibition in 11 dogs increased RVR by 32 +/- 4% and decreased renal blood flow (RBF) by 25 +/- 3%, outer cortical blood flow by 25 +/- 6%, urine flow by 37 +/- 14%, UNaV by 71 +/- 5%, and fractional excretion of sodium (FENa) by 71 +/- 4%. Glomerular filtration rate was not significantly changed during NLA infusion. As previously reported, there was suppression of the RBF autoregulation plateau during NO synthesis inhibition. In addition, there was a marked attenuation of urine flow and UNaV responses to reductions in RAP (150 to 75 mmHg), with significant reductions in the slopes of the relationships between RAP vs. UNaV and RAP vs. FENa during NLA infusion. Similar responses were observed in nine other dogs treated with the angiotensin receptor antagonist losartan, indicating that an augmented activity of the renin-angiotensin system is not responsible for attenuation of the slope of the pressure-natriuresis relationship during NLA infusion. These data suggest that NO may participate in the mediation of the pressure-natriuresis response.

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.

Lumped Parameter Thermal Model for the Study of Vascular Reactivity in the Fingertip

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
O. Ley ◽  
C. Deshpande ◽  
B. Prapamcham ◽  
M. Naghavi
Keyword(s):  
Heat Flux ◽  
Blood Flow ◽  
Thermal Model ◽  
Vascular Reactivity ◽  
Arterial Occlusion ◽  
Blood Perfusion ◽  
Cost Effective ◽  
Venous Occlusion ◽  
Cardiovascular Complications ◽  
Tissue Temperature

Vascular reactivity (VR) denotes changes in volumetric blood flow in response to arterial occlusion. Current techniques to study VR rely on monitoring blood flow parameters and serve to predict the risk of future cardiovascular complications. Because tissue temperature is directly impacted by blood flow, a simplified thermal model was developed to study the alterations in fingertip temperature during arterial occlusion and subsequent reperfusion (hyperemia). This work shows that fingertip temperature variation during VR test can be used as a cost-effective alternative to blood perfusion monitoring. The model developed introduces a function to approximate the temporal alterations in blood volume during VR tests. Parametric studies are performed to analyze the effects of blood perfusion alterations, as well as any environmental contribution to fingertip temperature. Experiments were performed on eight healthy volunteers to study the thermal effect of 3min of arterial occlusion and subsequent reperfusion (hyperemia). Fingertip temperature and heat flux were measured at the occluded and control fingers, and the finger blood perfusion was determined using venous occlusion plethysmography (VOP). The model was able to phenomenologically reproduce the experimental measurements. Significant variability was observed in the starting fingertip temperature and heat flux measurements among subjects. Difficulty in achieving thermal equilibration was observed, which indicates the important effect of initial temperature and thermal trend (i.e., vasoconstriction, vasodilatation, and oscillations).

A-85 Differences in Cerebral Blood Perfusion with Individuals Diagnosed with Cluster B Personality Disorders

2021 ◽  
Vol 36 (6) ◽  
pp. 1132-1132
Author(s):  
D'anna Sydow ◽  
Daniel Amen ◽  
Kristen Willeumier ◽  
Brittny Arias ◽  
Charles J Golden ◽  
...  
Keyword(s):  
Blood Flow ◽  
Basal Ganglia ◽  
Personality Disorders ◽  
Limbic System ◽  
Negative Emotion ◽  
Blood Perfusion ◽  
Healthy Controls ◽  
Self Recognition ◽  
Cluster B Personality Disorders ◽  
And Gender

Abstract Objective To identify regional cerebral blood flow (rCBF) differences between individuals with DSM-IV diagnosis of Cluster B Personality Disorders (PDB) and healthy controls. Method Healthy controls (n = 81, Mage = 41.9, 53.0% female, 42.0% Caucasian) and persons diagnosed by psychiatric examination with PDB (n=, Mage = 34.12, 71.5% female, 69.8% Caucasian) were selected from a deidentified adult clinical outpatient database. Those with comorbid diagnoses were included. Significant differences (alpha = 0.005) were found for age [t(195) = −3.62], gender [χ2(2) = 7.1], and race [χ2(12) = 23.82] between groups. Mean age [t(523) = 2.09, p = 0.037) and gender [t(532) = −2.653, p = 0.008] different significantly between groups. No significant mean difference was found for education [t(523) = 0.832, p = 0.406]. Results Significant rCBF differences were noted in the cerebellum [left:F(1,192) = 10.5; right:F(1,192) = 4.6], limbic system [left:F(1,192) = 7.8; right:F(1,192) = 5.0], and basal ganglia [left:F(1,192) = 12.3; right:F(1,192) = 6.7]. Group means comparisons indicated higher perfusion in the cerebellum for the PDB group. Lower perfusion was found in the limbic system and basal ganglia in the PDB group. Conclusion Results observed in this study are concurrent with previous literature. PDB demonstrates higher activity in the cerebellum which contains inhibitory neurotransmitters, like Purkinje cells. The increased blood flow to cerebellar circuits may be related to the explicit self-recognition of negative emotion reported in PDB. Hypoperfusion found in the limbic system could be linked to impaired emotional responses. Apathy experienced in PDB may be accounted for by the low perfusion in the highly dopaminergic pathway in the basal ganglia. Further research should assess how different comorbidities with PDB affect perfusion.

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