scholarly journals The role of pneumoperitoneum in the glomerular filtration in an experimental model with 2/3 reduction of the renal mass

2017 ◽  
Vol 39 (1) ◽  
pp. 89
Author(s):  
Marco Aurélio Valadão ◽  
Djalma José Fagundes ◽  
Willian Cesar Cavazana ◽  
Gabriel Jorge Fagundes

Objective: To evaluate the influence of the CO2 pneumoperitoneum in the glomerular filtration in a rat model with a 2/3 reduction of renal parenchyma. Methods: Adult Wistar male rats (n = 50) were subjected to right nephrectomy and a 2/3 ligature of the renal left vascular branch. Animals were randomly distributed as follows: GI (n = 10) - simulated, GII (n = 20) –8 mm Hg pneumoperitoneum, and GIII (n = 20) –15 mm Hg pneumoperitoneum. After two (GIIA and GIIIA) and three (GIIB and GIIIB) hours of insufflation, and one hour of disinsufflation, they were evaluated for the following aspects: mean blood pressure (MBP), microhematocrit, urinary volume and inulin clearance. Results: The microscopic aspects showed signs of glomerulosclerosis that caused proteinuria. Renal function with8 mm Hg pneumoperitoneum after two hours of disinsufflation (Δ% = 202.68) was better than after three hours (Δ% = 10.89). With15 mm Hg pneumoperitoneum, the renal function was damaged by both procedures, that is, two (Δ% = -3.57) and three hours (Δ% = -3.25). Conclusion: Inulin clearance evidenced renal insufficiency in the model with a 2/3 reduction of renal mass, and depending on both the increase of the exposure time and the pressure intensity, it can be more intensified. 

1990 ◽  
Vol 259 (5) ◽  
pp. F747-F751 ◽  
Author(s):  
S. B. Miller ◽  
V. A. Hansen ◽  
M. R. Hammerman

To characterize actions of growth hormone (GH) and insulin-like growth factor ( (IGF-I) on renal function in rats with normal and reduced renal mass, we administered recombinant bovine growth hormone (bGH) or human IGF-I (hIGF-I) to normal rats or to rats that had undergone unilateral nephrectomy and two-thirds infarction of the contralateral kidney, and measured inulin and p-aminohippurate clearances over 10-17 days. Administration of either bGH (100-200 micrograms/day) or hIGF-I (200 micrograms/day) to rats with normal renal mass increased inulin and p-aminohippurate clearances compared with those measured in animals that received vehicle. Filtration fractions were not affected by either bGH or hIGF-I. Inulin clearance was decreased to approximately 17% of normal 1 day after reduction of renal mass in rats. Over the next 3 days insulin clearance increased significantly in rats with reduced renal mass that were administered vehicle. No further enhancement occurred during the next 7 days. Neither bGH nor hIGF-I affected inulin clearance in rats with reduced renal mass. We conclude that both GH and IGF-I enhance glomerular filtration rate when administered to rats with normal renal mass, but not when administered in the same quantities to rats in which renal functional mass is reduced. Glomerular filtration rate increases within 4 days of renal mass reduction independent of exogenous GH or IGF-I.


2021 ◽  
Vol 19 (4) ◽  
Author(s):  
О.А. Olenovych

The aim of the study – to explore the role of the renin-angiotensin-aldosteronesystem (RAAS) in the disturbance of ionoregulatory renal function in alloxan-inducedexperimental diabetes mellitus (EDM).Material and methods. The experiments were carried out on 78 white non-linearmature male rats with 11-, 26- and 46-day long alloxan-induced EDM with underlyingpharmacological blockade of RAAS by administration of kaptopril. The study ofionoregulating function of the kidneys was provided by the clearance method under thecondition of water 2-hour diuresis.Results. Pharmacological blockade of RAAS in rats with alloxan-induced EDM causedan intensification of natriuresis at all stages of the experiment: increased urinaryconcentration of sodium ions, its excretion and clearance. On the 11th day of EDM, thesodium filtration charge increased with the development of hyponatremia, proximal anddistal sodium reabsorption standardized in volume of glomerular filtrate (GF) decreased,kaliuresis was suppressed, and sodium-free water clearance elevated. In case of 26-daylong EDM, the sodium filtration charge decreased, its absolute and relative reabsorption,the distal sodium reabsorption standardized by GF increased. Kaliuresis increased. In46-day long EDM, the sodium filtration charge decreased, and hyponatremia enhanced.Absolute and relative sodium reabsorption reduced due to both – proximal and distal.Kaliuresis augmented, the clearance of sodium-free water declined.Conclusions. The increase in urinary sodium loss during the 11-day EDM is stipulatedby glomerular hyperfiltration, causing a functional weakening of the tubulotubularbalance and relative dysfunction of the distal segment of the nephron, emphasizing therenoprotective effect of RAAS on ionoregulatory function of the kidneys. The decrease inthe total reabsorption potential of the tubular segment of the nephron in the dynamics ofEDM development reflects on the proximal tubules, and preserved tubulotubular balancecertifies functional intactness of the distal tubules in 26-day long EDM. RAAS pathologicalactivation and attenuation of the renal blood flow autoregulation by tubuloglomerularfeedback may serve as an initiating factor in the development of tubular disorders in 26-day long alloxan diabetes with following progression in 46-day long EDM.


Author(s):  
Thomas G Morris ◽  
Sushmita Lamba ◽  
Thomas Fitzgerald ◽  
Gary Roulston ◽  
Helen Johnstone ◽  
...  

Background Differentiating between true and pseudohyperkalaemia is essential for patient management. The common causes of pseudohyperkalaemia include haemolysis, blood cell dyscrasias and EDTA contamination. One approach to differentiate between them is by checking the renal function, as it is believed that true hyperkalaemia is rare with normal function. This is logical, but there is limited published evidence to support it. The aim of this study was to investigate the potential role of the estimated glomerular filtration rate in differentiating true from pseudohyperkalaemia. Methods GP serum potassium results >6.0 mmol/L from 1 January 2017 to 31 December 2017, with a repeat within seven days, were included. Entries were retrospectively classified as true or pseudohyperkalaemia based on the potassium reference change value and reference interval. If the initial sample had a full blood count, it was classified as normal/abnormal to remove blood cell dyscrasias. Different estimated glomerular filtration rate cut-points were used to determine the potential in differentiating true from pseudohyperkalaemia. Results A total of 272 patients were included with potassium results >6.0 mmol/L, with 145 classified as pseudohyperkalaemia. At an estimated glomerular filtration rate of 90 ml/min/1.73 m2, the negative predictive value was 81% (95% CI: 67–90%); this increased to 86% (95% CI: 66–95%) by removing patients with abnormal full blood counts. When only patients with an initial potassium ≥6.5 mmol/L were included (regardless of full blood count), at an estimated glomerular filtration rate of 90 ml/min/1.73 m2, the negative predictive value was 100%. Lower negative predictive values were seen with decreasing estimated glomerular filtration rate cut-points. Conclusion Normal renal function was not associated with true hyperkalaemia, making the estimated glomerular filtration rate a useful tool in predicting true from pseudohyperkalaemia, especially for potassium results ≥6.5 mmol/L.


2021 ◽  
Author(s):  
Rui Sasaki ◽  
Katsuhisa Sunada

Abstract Objective We investigated the role of epinephrine in prolonging the localization of a topical anesthetic on oral mucosa and inhibiting its absorption in blood. Methods We used 7–8-week-old specific-pathogen-free Wistar male rats (n = 128) for our study. We divided them into lidocaine and lidocaine with epinephrine groups and applied 5 µL of 14C-labeled lidocaine hydrochloride gel and 10 µg/mL 14C-labeled lidocaine hydrochloride gel with added epinephrine to the palatal mucosae of the rats, respectively. The amount of lidocaine was measured by radioactivity and was observed using autoradiograms. Results After 4 min, the values were significantly lower in the lidocaine with epinephrine group (1040.0 ± 142.8 vs. 701.2 ± 109.0 ng/mg [20 min]). After 40 min, the lidocaine level became significantly higher in the lidocaine with epinephrine group (586.8 ± 112.4 vs. 1131.3 ± 155.2 ng/mg [40 min]). Similar results were observed in the palatine bone and mucosa and serum. Conclusion Epinephrine prolonged the localization of lidocaine applied to the mucosa and inhibited its absorption into the bloodstream. Clinical studies are required to evaluate the use of epinephrine-containing topical anesthetics on the oral mucosa.


1977 ◽  
Vol 73 (1) ◽  
pp. 31-36 ◽  
Author(s):  
J. P. MTABAJI ◽  
C. J. ROBINSON ◽  
M. S. MANKU ◽  
D. CRONIN ◽  
D. F. HORROBIN

SUMMARY To test the effect of prostaglandin A2 (PGA2) on renal function, infusions of PGA2 (0·7 ng/ kg/min), arginine-vasopressin (AVP) (1·25 ng/kg/min) and PGA2 plus AVP were administered to male rats made resistant to the antidiuretic effect of AVP by pre-treatment with lithium. In non-lithium-treated control rats, AVP had its expected antidiuretic action but in lithium-treated rats neither urinary volume nor osmolarity was changed. Prostaglandin A2 alone had no effect on urine output in lithium-treated rats; AVP plus PGA2 infused together evoked a near normal antidiuretic response. This antidiuretic action of PGA2 contrasts with the diuretic action reported by others. However, our infusion rates were 300–4000 times lower than those of other workers and it is suggested that PGs may have opposite actions on the kidney depending on their concentration. The effect of indomethacin (a blocker of prostaglandin synthesis) on urine flow was tested in five groups of rats on different régimes of liquid intake. Urine flow was reduced in the three groups with the highest urine volumes before treatment, and increased in the two groups with the lowest urinary volumes, again indicating that PGs may have both diuretic and antidiuretic actions.


1989 ◽  
Vol 35 (2) ◽  
pp. 312-314 ◽  
Author(s):  
F S Apple ◽  
P Benson ◽  
P A Abraham ◽  
T G Rosano ◽  
C E Halstenson

Abstract We compared creatinine clearances determined by enzymatic (Kodak Ektachem 700 single-slide, Boehringer Mannheim creatinine PAP) and nonenzymatic (Jaffé, HPLC) methods with glomerular filtration rate measured by inulin clearance in patients with varying degrees of renal function. The Kodak enzymatic assay gave values for creatinine 2 to 3 mg/L higher than the other methods. This resulted in significantly lower creatinine clearances than inulin clearances and creatinine clearances determined by the other methods. However, correlations between all methods for serum and urinary creatinine values and clearances were good. To avoid between assay (enzymatic vs nonenzymatic) discrepancies, manufacturers should agree to an acceptable standard of calibration under the usual conditions used with patients.


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