Renal extraction of glucagon in rats with normal and reduced renal function

1977 ◽  
Vol 233 (1) ◽  
pp. F67-F71 ◽  
Author(s):  
C. Bastl ◽  
F. O. Finkelstein ◽  
R. Sherwin ◽  
R. Hendler ◽  
P. Felig ◽  
...  

To examine the role of the kidney in the mechanism of impaired metabolic clearance of glucagon in renal failure, the renal handling of endogenous pancreatic glucagon was studied in rats with normal renal function and rats with renal insufficiency produced by 70% surgical ablation. Mean +/- SE renal extraction of glucagon in animals with normal renal function was 39 +/- 5%. Urinary losses of glucagon accounted for less than 2% of renal extraction. In contrast, in the animals with renal insufficiency (glomerular filtration rate reduced to one-third of normal), arterial glucagon increased 40% and renal extraction and extraction rate per gram kidney weight of glucagon were negligible, despite filtered loads of 204 +/- 42 pg/min per g kidney wt. These findings indicate a major role of the kidney in the metabolic clearance of glucagon under normal conditions and suggest that during renal insufficiency elevated plasma levels of glucagon occur, at least in part, as a result of a decreased renal turnover of the hormone.

1965 ◽  
Vol 48 (3) ◽  
pp. 348-354 ◽  
Author(s):  
Thomas Falkheden ◽  
Ingmar Wickbom

ABSTRACT Measurements of glomerular filtration rate (GFR) and renal plasma flow (RPF) were performed in close connection with roentgenographic estimation of kidney size, before and after hypophysectomy, in 10 patients (four cases of metastatic mammary carcinoma, five cases of diabetic retinopathy and one case of acromegaly). Hypophysectomy was regularly followed by a decrease in GFR and RPF. In most cases, a reduction in the roentgenographic kidney size was also observed. However, the changes in the roentgenographic kidney size and calculated kidney weight after hypophysectomy were smaller and occurred at a slower rate than the alterations in GFR and RPF. The results favour the view that, primarily, the decrease in GFR and RPF following hypophysectomy is essentially functional rather than due to a reduced kidney mass.


PEDIATRICS ◽  
1991 ◽  
Vol 87 (2) ◽  
pp. 148-151
Author(s):  
V. Marc Tsou ◽  
Rose M. Young ◽  
Michael H. Hart ◽  
Jon A. Vanderhoof

Aluminum toxicity is a documented cause of encephalopathy, anemia, and osteomalacia. Excretion is primarily renal; therefore, patients with renal insufficiency are at risk for aluminum accumulation and toxicity. This has been demonstrated in uremic children treated with aluminum-containing antacids. The purpose of this study was to determine whether plasma aluminum levels were elevated in infants with normal renal function during prolonged aluminum-containing antacid use. Ten study infants (mean age = 5.8 months), who had been receiving antacids for at least 1 week, were compared with 16 control infants (mean age = 9.8 months) not receiving antacids. The study patients consumed 123 ± 16 mg/kg per day (mean ± SEM) of elemental aluminum for an average of 4.7 weeks. Their plasma aluminum level (37.2 ± 7.13 µg/L) was significantly greater than that of the control group (4.13 ± 0.66 µg/L) (P < .005). It is concluded that plasma aluminum levels may become elevated in infants with normal renal function who are consuming high doses of aluminum-containing antacids. The safety of antacids containing aluminum should not be assumed and they should be used judiciously in infants, with careful monitoring of the aluminum dose and plasma level.


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.


2016 ◽  
Vol 61 (1) ◽  
Author(s):  
Visanu Thamlikitkul ◽  
Yanina Dubrovskaya ◽  
Pooja Manchandani ◽  
Thundon Ngamprasertchai ◽  
Adhiratha Boonyasiri ◽  
...  

ABSTRACT Polymyxin B remains the last-line treatment option for multidrug-resistant Gram-negative bacterial infections. Current U.S. Food and Drug Administration-approved prescribing information recommends that polymyxin B dosing should be adjusted according to the patient's renal function, despite studies that have shown poor correlation between creatinine and polymyxin B clearance. The objective of the present study was to determine whether steady-state polymyxin B exposures in patients with normal renal function were different from those in patients with renal insufficiency. Nineteen adult patients who received intravenous polymyxin B (1.5 to 2.5 mg/kg [actual body weight] daily) were included. To measure polymyxin B concentrations, serial blood samples were obtained from each patient after receiving polymyxin B for at least 48 h. The primary outcome was polymyxin B exposure at steady state, as reflected by the area under the concentration-time curve (AUC) over 24 h. Five patients had normal renal function (estimated creatinine clearance [CLCR] ≥ 80 ml/min) at baseline, whereas 14 had renal insufficiency (CLCR < 80 ml/min). The mean AUC of polymyxin B ± the standard deviation in the normal renal function cohort was 63.5 ± 16.6 mg·h/liter compared to 56.0 ± 17.5 mg·h/liter in the renal insufficiency cohort (P = 0.42). Adjusting the AUC for the daily dose (in mg/kg of actual body weight) did not result in a significant difference (28.6 ± 7.0 mg·h/liter versus 29.7 ± 11.2 mg·h/liter, P = 0.80). Polymyxin B exposures in patients with normal and impaired renal function after receiving standard dosing of polymyxin B were comparable. Polymyxin B dosing adjustment in patients with renal insufficiency should be reexamined.


2003 ◽  
pp. 597-602 ◽  
Author(s):  
H Yamashita ◽  
S Noguchi ◽  
S Uchino ◽  
S Watanabe ◽  
T Murakami ◽  
...  

OBJECTIVE: Disturbed renal function may play an important role in the clinico-pathological presentation of primary hyperparathyroidism (pHPT). We studied the influence of renal function on the clinico-pathological characteristics of 141 patients (123 women and 18 men) with surgically proven pHPT. METHODS: The 141 patients were assigned to one of two groups based on creatinine clearance (C(cr)) level: a renal insufficiency group (n=37) in which C(cr) of patients was <70 ml/min and a normal renal function group (n=104) in which C(cr) was > or =70 ml/min. Clinical presentation and biochemical indices were evaluated and compared between the two groups. RESULTS: Age, and frequency of hypertension and of diabetes mellitus were significantly (P<0.001, P<0.05 and P<0.05 respectively) higher in the renal insufficiency group than in the normal renal function group. Serum levels of calcium, intact parathyroid hormone and bone Gla protein were significantly (P<0.05) higher and the excised parathyroid weighed significantly more (P<0.05) in the renal insufficiency group than in the normal renal function group; however, serum 1,25-dihydroxyvitamin D (1,25(OH)(2)D) and 24 h urinary calcium excretion were significantly (P<0.001 and P<0.05 respectively) lower in the former than in the latter group. There was a significant inverse correlation between C(cr) level and serum calcium (r=0.315, P<0.001) and a significant positive correlation between C(cr) level, 1,25(OH)(2)D (r=0.315, P<0.001), and 24 h calcium excretion (r=0.458, P<0.0001). CONCLUSIONS: Clinico-pathological features of pHPT were notably influenced by even moderate renal insufficiency. Urinary calcium excretion decreased according to the decrease in glomerular filtration rate. Therefore, endocrinologists need to appraise urinary calcium excretion and renal function of pHPT patients when considering surgery or in discriminating familial hypocalciuric hypercalcemia.


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