scholarly journals Renal Function and Urine Production in the Compromised Fetus

10.5772/29098 ◽  
2012 ◽  
Author(s):  
Mats Fagerquist
Keyword(s):  
Renal Function ◽  
Urine Production

Fluid secretion in glomerular renal proximal tubules of freshwater-adapted fish

1988 ◽  
Vol 254 (1) ◽  
pp. R154-R158 ◽  
Author(s):  
W. H. Cliff ◽  
K. W. Beyenbach
Keyword(s):  
Renal Function ◽  
Fluid Secretion ◽  
Tubular Secretion ◽  
Hormonal Control ◽  
Proximal Tubules ◽  
Renal Proximal Tubules ◽  
Urine Production ◽  
Nacl Secretion ◽  
Urine Formation ◽  
Control Fluid

Tubular secretion by renal proximal tubules, as a mechanism for delivering fluid and electrolytes to the urine, has received little attention in modern conceptions of renal function in vertebrates even though it is the mechanism for urine production in aglomerular fish. This report demonstrates that some proximal tubules of glomerular kidneys of freshwater-adapted euryhaline fish spontaneously secrete fluid. The fluid consists primarily of Na (138 mM) and Cl (160 mM). NaCl and fluid secretion can be stimulated by adenosine 3',5-cyclic monophosphate, suggesting that tubular fluid secretion is under hormonal control. Fluid secretion driven by NaCl secretion in glomerular proximal tubules of fish that already filter NaCl and water suggests that secretion of fluid and NaCl may play a fundamental role in vertebrate renal function beyond a preadaptation for aglomerular urine formation.

Nocturnal Polyuria: Excess of Nocturnal Urine Production, Excess of Definitions—Influence on Renal Function Profile

2016 ◽  
Vol 195 (3) ◽  
pp. 670-676 ◽  
Author(s):  
An-Sofie Goessaert ◽  
Johan Vande Walle ◽  
Ruud Bosch ◽  
Piet Hoebeke ◽  
Karel Everaert
Keyword(s):  
Renal Function ◽  
Nocturnal Polyuria ◽  
Urine Production ◽  
Function Profile

Electrolyte and Water Balance in Plasma and Urine of Rainbow Trout (Salmo gairdneri) during Chronic Exposure to Cadmium

1984 ◽  
Vol 41 (11) ◽  
pp. 1678-1685 ◽  
Author(s):  
Michael A. Giles
Keyword(s):  
Renal Function ◽  
Rainbow Trout ◽  
Water Balance ◽  
Chronic Exposure ◽  
Plasma Calcium ◽  
Salmo Gairdneri ◽  
Plasma Sodium ◽  
Sodium Potassium ◽  
Urine Production ◽  
Calcium And Magnesium

Rainbow trout (Salmo gairdneri) were exposed to 3.6 and 6.4 μg Cd/L for periods up to 178 d. Transitory changes in plasma calcium and magnesium were observed in fish exposed to 3.6 μg Cd/L although the differences were not significant. Exposure to 6.4 μg Cd/L, however, resulted in significantly lowered plasma sodium, potassium, calcium, and chloride and elevated magnesium concentrations. Analyses of urine indicated that the rate of urine production, osmolality, and sodium, potassium, chloride, magnesium, calcium, and protein concentrations were unaffected by exposure to 3.6 μg Cd/L although slight changes were observed in the first week of exposure. Urine production rate and urinary concentrations of potassium and chloride were unaffected in trout exposed to 6.4 μg Cd/L but sodium, protein, and osmolality were elevated and calcium and magnesium concentrations reduced in these fish. The results demonstrate that the majority of the cadmium-induced electrolyte imbalances do not result from impairment of renal function.

scholarly journals Impact of Alternative Routes and Timing of Dopamine and Mannitol Administrations to Reduce Negative Properties of Extended Cardiopulmonary Bypass on Renal Function in Coronary Artery Operations

2021 ◽  
pp. 307-312
Author(s):  
Iqra Ejaz ◽  
Salwa Naeem ◽  
Mian Seher Munir ◽  
Muhammad Usman ◽  
Sohail Zafar ◽  
...  
Keyword(s):  
Renal Function ◽  
Cardiopulmonary Bypass ◽  
Coronary Artery ◽  
Group Iv ◽  
Anesthetic Induction ◽  
Group Iii ◽  
Urine Production ◽  
Alternative Routes ◽  
Actual Method ◽  
Substantial Rise

Objectives: To analyze impact of alternative routes and timing of dopamine and mannitol administrations to reduce negative properties of extended cardiopulmonary bypass on renal function in coronary artery operations. Methods: Set I (n: 26 individual): Mannitol (1 g/kg) has been introduced to the CPB priming solution. Set II (n: 25 patients): Even during interval among anesthetic induction and operation, 3 g/kg/min of IV dopamine was delivered. Group III (n = 25 patients): 2 g/kg/min IV dopamine was provided among anesthesia initiation and operation conclusion, and 1 g/kg mannitol were added to priming solution for CPB. Furosemide was administered to Group IV (n = 26 cases) when urine production was poor. Results: There would be a substantial rise in the post-operative urine microalbumin/creatinine ratios over all classes (p 0.06), as well as a rise in cystatin-c in Set 1, 2, and 3 (p 0.02). Conclusions: Researchers suggest that combining dopamine infusion (1 g/kg/min) and mannitol (2 g/kg) throughout CPB seems to be the more actual method for preventing detrimental possessions of CPB on renal functioning.

The Relationship between Kt/VUrea and Npna in Anuric Peritoneal Dialysis Patients: A Comparison with Predialysis Patients

2001 ◽  
Vol 21 (5) ◽  
pp. 509-515 ◽  
Author(s):  
◽  
Maarten A.M. Jansen ◽  
Johanna C. Korevaar ◽  
Friedo W. Dekker ◽  
Kitty J. Jager ◽  
...  
Keyword(s):  
Renal Function ◽  
Peritoneal Dialysis ◽  
Residual Renal Function ◽  
Control Group ◽  
Dialysis Patients ◽  
Urea Clearance ◽  
Linear Relationships ◽  
Significant Difference ◽  
Urine Production ◽  
The Relationship

Objective It is unknown whether a given level of urea clearance by the native kidneys provides better or similar control of uremia than the same level of urea clearance by continuous peritoneal dialysis (PD). More insight into possible differences between renal and peritoneal urea clearances is warranted. Therefore, we investigated the relationship between Kt/Vurea and protein equivalent of total nitrogen appearance normalized to body weight (nPNA), the relationship between urea clearance and creatinine appearance, and other nutritional parameters in PD patients without residual renal function, and in predialysis end-stage renal disease patients. Patients All patients participated in the Netherlands Cooperative Study on the Adequacy of Dialysis. This is a prospective cohort study of incident dialysis patients, in whom regular assessments of renal function are done. A group of 75 PD patients was identified at the first follow-up assessment in which their urine production was less than 100 mL/day. These patients were considered the anuric group. This group was compared with a control group of 97 predialysis patients studied 0 – 4 weeks before the start of dialysis treatment. Results Linear relationships were present between Kt/Vurea and nPNA, in both the predialysis patients and the anuric PD patients. A significant difference was present between the slopes of the two regression lines (0.40 vs 0.18, p = 0.007). When Kt/Vurea exceeded 1.3/week, a given level of Kt/Vurea was associated with a higher nPNA in predialysis than in anuric PD patients. Similar relationships were found between Kturea and PNA. Kturea was also significantly related to urine or dialysate creatinine appearance. A significant difference existed between the slopes of the regression lines in the two groups of patients ( p < 0.001). A weekly Kturea of 70 L was associated with a urine creatinine appearance of 11.0 mmol/day and a dialysate creatinine appearance of 8.4 mmol/day. Nutritional status measured with creatinine appearance and Subjective Global Assessment was better in the predialysis population, despite much lower values for Kt/Vurea in these patients. Conclusions The relationship between Kt/Vurea and nPNA in anuric PD patients is different from that in a predialysis population. It follows from our results that, when Kt/Vurea is above 1.3/week, a given level of Kt/Vurea is associated with a higher nPNA in predialysis than in anuric PD patients. This challenges the concept of equivalency between renal and peritoneal Kt/Vurea with respect to control of uremic morbidity.

Determination of the Preferred Conditions for the Isolated Perfusion of Porcine Kidneys

2014 ◽  
Vol 54 (1-2) ◽  
pp. 44-54 ◽  
Author(s):  
Elina Mancina ◽  
Julia Kalenski ◽  
Pascal Paschenda ◽  
Christian Beckers ◽  
Christian Bleilevens ◽  
...  
Keyword(s):  
Renal Function ◽  
Structural Integrity ◽  
Ex Vivo ◽  
Fractional Excretion ◽  
Pure Oxygen ◽  
Kidney Graft ◽  
Kidney Preservation ◽  
Fractional Excretion Of Sodium ◽  
Urine Production ◽  
Pressure Controlled

Background: The isolated perfused porcine kidney (IPPK) model has been the method of choice for the early preclinical evaluation of kidney graft preservation techniques. The preferred reperfusion conditions have not yet been determined. Here, we examined the effects of pressure- or flow-controlled perfusion and oxygenation by pure oxygen or carbogen (95% O2/5% CO2) on normothermic reperfusion in the IPPK model. Methods: Porcine kidneys were cold-stored for 24 h in histidine-tryptophan-ketoglutarate solution and reperfused for 1 h with normothermic whole blood/Krebs-Henseleit buffer medium (20/80%). Kidneys (n = 5/group) were flow-controlled reperfused with pure oxygen (1 ml/min/g; Flow-O2) or pressure-controlled reperfused (85 mm Hg mean arterial pressure) and oxygenated with either pure oxygen (Pressure-O2) or carbogen (Pressure-O2/CO2). Renal function and damage were assessed during reperfusion and NGAL and HIF-1α levels were analyzed using an ELISA. Results: Pressure-O2 and Pressure-O2/CO2 were associated with significantly better renal hemodynamics and acid-base homeostasis compared to Flow-O2. Urine protein concentrations and the fractional excretion of sodium were lower with both Pressure-O2 and Pressure-O2/CO2 than with Flow-O2. NGAL and HIF-1α levels were also lower with Pressure-O2 and Pressure-O2/CO2 than with Flow-O2. Only Pressure-O2/CO2 could demonstrate a significantly increased urine production compared to Flow-O2. The structural integrity was well preserved in the Pressure-O2 and Pressure-O2/CO2 groups, whereas diffuse and global glomerular destruction was observed in the Flow-O2 group. Conclusion: In the IPPK model, the application of pressure-controlled reperfusion with carbogen oxygenation, and to a lesser extent with pure oxygen, maintained physiological renal function for 1 h, thus providing a reliable and reproducible ex vivo evaluation of kidney preservation quality.

Changes in Renal Function During Induced Apnea of Diffusion Respiration

1958 ◽  
Vol 194 (1) ◽  
pp. 143-148 ◽  
Author(s):  
V. C. Bohr ◽  
R. J. Ralls ◽  
R. E. Westermeyer
Keyword(s):  
Renal Function ◽  
Renal Pedicle ◽  
Blood Ph ◽  
Urine Production ◽  
Thiopental Sodium ◽  
Adequate Oxygenation ◽  
Spinal Hemisection

If apnea is induced in dogs by overdoses of thiopental sodium, urine production will be greatly diminished or totally cease, despite good hydration, normotensive arterial pressures and adequate oxygenation of the animals by means of diffusion respiration. This oliguria or anuria can be largely reversed by infusion of osmotic diuretics, although mercurial-xanthene diuretics and Diamox diuretics do not alter the course of the developing anuria. Likewise, unilateral surgical stripping of the renal pedicle, unilateral splanchnicectomy, or spinal hemisection cause the kidneys on the side of the lesions to continue to produce urine after the contralateral intact kidneys become anuric. The clearances of PAH and creatinine are depressed in both intact and surgically denervated kidneys during the apnea. However, the depression is very much less in the denervated kidneys. A diminution in PAH extraction ratios, which appear to correlate with a drop in blood pH, was also observed.

scholarly journals A computational analysis of the long-term regulation of arterial pressure

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 208 ◽  
Author(s):  
Daniel A. Beard ◽  
Klas H. Pettersen ◽  
Brian E. Carlson ◽  
Stig W. Omholt ◽  
Scott M. Bugenhagen
Keyword(s):  
Blood Pressure ◽  
Renal Function ◽  
Arterial Pressure ◽  
Dominant Role ◽  
Renin Angiotensin System ◽  
Primary Hypertension ◽  
Model Parameters ◽  
Arterial Blood ◽  
Urine Production

The asserted dominant role of the kidneys in the chronic regulation of blood pressure and in the etiology of hypertension has been debated since the 1970s. At the center of the theory is the observation that the acute relationships between arterial pressure and urine production—the acute pressure-diuresis and pressure-natriuresis curves—physiologically adapt to perturbations in pressure and/or changes in the rate of salt and volume intake. These adaptations, modulated by various interacting neurohumoral mechanisms, result in chronic relationships between water and salt excretion and pressure that are much steeper than the acute relationships. While the view that renal function is the dominant controller of arterial pressure has been supported by computer models of the cardiovascular system known as the “Guyton-Coleman model”, no unambiguous description of a computer model capturing chronic adaptation of acute renal function in blood pressure control has been presented. Here, such a model is developed with the goals of: 1. capturing the relevant mechanisms in an identifiable mathematical model; 2. identifying model parameters using appropriate data; 3. validating model predictions in comparison to data; and 4. probing hypotheses regarding the long-term control of arterial pressure and the etiology of primary hypertension. The developed model reveals: long-term control of arterial blood pressure is primarily through the baroreflex arc and the renin-angiotensin system; and arterial stiffening provides a sufficient explanation for the etiology of primary hypertension associated with ageing. Furthermore, the model provides the first consistent explanation of the physiological response to chronic stimulation of the baroreflex.

Renal Function in the Spectacled Hare-Wallaby, Lagorchestes conspicillatus: Effects of Dehydration and Protein Deficiency

1983 ◽  
Vol 31 (2) ◽  
pp. 101 ◽  
Author(s):  
HR Bakker ◽  
SD Bradshaw
Keyword(s):  
Renal Function ◽  
Glomerular Filtration ◽  
Protein Intake ◽  
Protein Diet ◽  
Inulin Clearance ◽  
Field Observations ◽  
Clearance Ratio ◽  
Low Protein ◽  
Urine Production ◽  
Protein Diets

Renal function was studied in a marsupial, the spectacled hare-wallaby Lagorchestes conspicillatus, and the effects of acute dehydration and exposure to a low-protein diet assessed. The rate of glomerular filtration (GFR), measured as the inulin clearance, fell significantly with both treatments but tubular function was unaffected. This reduction in GFR accounted entirely for the antidiuresis observed with both dehydration and exposure to low-protein intake and accords with field observations of the hare- wallaby, where urine volumes are characteristically low and have low osmolalities. When data from animals on both high and low-protein diets were considered together, the clearance ratio for urea (C*urea/C*in) was found to be positively correlated with the rate of urine production, and it is evident that mechanisms which invoke antidiuresis in this species will automatically enhance the reabsorption of urea.

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