Renal Handling of Lithium and the Effects of Mannitol and Arginine Vasopressin in man

1995 ◽  
Vol 89 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Faruq H. Noormohamed ◽  
Ariel F. Lant
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Flow Rate ◽  
Arginine Vasopressin ◽  
Filtration Rate ◽  
Free Water ◽  
Fractional Excretion ◽  
Renal Handling ◽  
Fractional Clearance ◽  
Induced Changes

1. A study has been undertaken in six healthy male subjects to clarify whether post-proximal segments of the nephron contribute to the renal handling of lithium under conditions of maximal forced osmotic load diuresis and arginine vasopressin-induced antidiuresis. Increments in the fractional clearance of free water, as a measure of effect at the proximal tubule, were positively correlated with incremental changes in flow rate, factored for glomerular filtration rate (mean r = 0.80 ± 0.12, P < 0.001), and fractional excretion of lithium (mean r = 0.84 ± 0.06, P < 0.001). Changes in flow rate and fractional excretion of lithium were also closely correlated with one another (mean r = 0.81 ± 0.06, P < 0.001), and the mean slope of these regression lines was not significantly different from unity (1.18; 95% confidence interval 0.76–1.59). These results show that, under conditions of maximal hydration, mannitol-induced changes in proximal tubular function were closely correlated with induced changes in the fractional excretion of lithium. 2. Infusion of arginine vasopressin alone (0.5 m-units/min) caused a marked reduction in both fractional clearance of free water (10.7% ± 1.2% to −1.2% ± 0.2%, P < 0.001) and flow rate factored for glomerular filtration rate (14.0 ± 1.5 to 0.8 ± 0.2%; P < 0.001) while the fractional excretion of lithium showed only a small non-significant decrease (25.3% ± 2.0% to 23.3% ± 2.2%). A similar dissociation was noted between fluid and lithium excretion when arginine vasopressin was superimposed on mannitol infusion with reductions in the fractional clearance of free water (12.7% ± 1.0% to −0.9% ± 0.7%, P < 0.001) and flow rate (18.6% ± 1.5% to 5.7% ± 1.0%; P < 0.001), while the fractional excretion of lithium showed a significant increase (28.4% ± 1.7% to 33.1% ± 2.4%; P < 0.05). The lack of correlation between fluid and lithium excretion, in the presence of arginine vasopressin with or without mannitol, indicates that the late distal tubule and collecting duct have little or no significant capacity to reabsorb lithium. 3. These findings, taken as a whole, strengthen the view that renal tubular handling of lithium is primarily a proximal event.

Effect of Prolactin on Glomerular Filtration Rate

1978 ◽  
Vol 55 (4) ◽  
pp. 335-339 ◽  
Author(s):  
A. L. Riley ◽  
T. C. Hagen ◽  
J. E. Stefaniak
Keyword(s):  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Free Water ◽  
Flow Distribution ◽  
Fractional Excretion ◽  
Free Water Clearance ◽  
Fractional Excretion Of Sodium ◽  
Ovine Prolactin

1. The effect of infusion of ovine prolactin was studied in anaesthetized dogs pretreated with bromocryptine to reduce the release of endogenous prolactin. 2. Prolactin, injected intravenously and also directly into one kidney, resulted in a 12–18% increase in glomerular filtration rate (GFR) by both kidneys. 3. This increased GFR was not associated with any demonstrable changes in whole-kidney blood flow, distribution of intrarenal blood flow, fractional excretion of sodium or osmolar or free-water clearance. 4. We conclude that ovine prolactin produced an increase in GFR not dependent on an increase in whole-kidney plasma flow.

Effects of water load on renal glomerular and tubular function in desert quail

1975 ◽  
Vol 229 (1) ◽  
pp. 222-228 ◽  
Author(s):  
EJ Braun ◽  
WH Dantzler
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Flow Rate ◽  
Filtration Rate ◽  
Free Water ◽  
Urine Flow ◽  
Tubular Function ◽  
Free Water Clearance ◽  
Water Load ◽  
Single Nephron

Effects of an acute intravenous water load on glomerular and tubular function were studied in the anesthetized desert quail Lophortyx gambelii. Total-kidney glomerular filtration rate (GFR) and single-nephron glomerular filtration rates (SNGFR) of reptilian-type and mammalian-type nephrons increased by more than 50% compared with the GFR and SNGFRs measured during a control mannitol diuresis. Despite the increase in GFR, urine flow rate was only 56% of that in control mannitol diuresis, free-water clearance (CH2o) remained at 1-2% of GFR, and the animals excreted only about 79% of the water load. More than 99% of the filtered sodium and 93% of the filtered water were reabsorbed during the water load. Possible reasons for the increased GFR and the failure to produce a dilute urine or excrete the water load are discussed.

Compensatory renal hypertrophy in dogs: single nephron glomerular filtration rate

1977 ◽  
Vol 55 (1) ◽  
pp. 105-110 ◽  
Author(s):  
Serge Carrière ◽  
Michèle Gagnan-Brunette
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Left Kidney ◽  
Urine Volume ◽  
Free Water ◽  
Fractional Excretion ◽  
Fractional Excretion Of Sodium ◽  
Significant Difference ◽  
Single Nephron

Sodium ferrocyanide was used to measure the intrarenal distribution of single nephron glomerular filtration rate (SNGFR) in remaining kidneys of dogs, 10 d after contralateral nephrectomy. It was first demonstrated that the renal function of both kidneys in situ was comparable. Following right nephrectomy, the urine volume, p-aminohippuric acid clearance, creatine clearance, osmolar clearance, fractional excretion of potassium, and sodium excretion of the left kidney increased. Fractional excretion of sodium, free water clearance, and filtration fraction remained unchanged. Following that 10-d period, left kidney weight exceeded that of the previously removed contralateral kidney by 50%, indicating that most of the compensatory hypertrophy had already occurred. No significant difference in the length of the proximal tubule nor in the diameter of the glomeruli of superficial (SUP) and juxtamedullary (JM) nephrons of either kidney could be demonstrated. Most importantly, the ratio of radioactivity in the SUP/JM nephrons of the residual kidney was comparable with that previously observed in normal dog kidneys. Thus, the increase in total kidney GFR is explained through a proportional increase in the SNGFR of the SUP and JM nephrons.

Effect of acute hypercapnia on PTH-stimulated phosphaturia in dietary Pi-deprived rat

1987 ◽  
Vol 253 (1) ◽  
pp. F34-F40 ◽  
Author(s):  
J. Guntupalli ◽  
B. Matthews ◽  
B. Carlin ◽  
E. Bourke
Keyword(s):  
Glomerular Filtration Rate ◽  
Parathyroid Hormone ◽  
Glomerular Filtration ◽  
Inorganic Phosphate ◽  
Filtration Rate ◽  
Direct Evidence ◽  
Respiratory Acidosis ◽  
Urinary Ph ◽  
Renal Handling ◽  
Per Se

The effects of respiratory acidosis on renal inorganic phosphate (Pi) handling are controversial. Clearance experiments, therefore, were performed in fasted, chronically parathyroidectomized (PTX), dietary Pi-deprived rats. The objectives were twofold: to study the effects of compensated and uncompensated hypercapnia per se on renal Pi excretion and to examine the interaction between acute hypercapnia, dietary Pi, and parathyroid hormone (PTH) on the renal handling of Pi. Acute hypercapnia increased the plasma Pi (delta 2.82 +/- 0.65 mg/dl, P less than 0.05) without altering the glomerular filtration rate (GFR). The FEPi increased (delta 7.26 +/- 0.48%, P less than 0.001) but the TRPi/GFR also increased. PTH (3 U X kg-1 X h-1) superimposed on hypercapnia resulted in a plasma Pi comparable to hypercapnia alone. The FEPi (7.56 +/- 0.78 vs. 24.43 +/- 2.20%; P less than 0.001) was higher and the TRPi/GFR (117 +/- 4 vs. 80 +/- 2 micrograms/min, P less than 0.01) lower, in the former group. PTH infusion during normocapnia resulted in a lower FEPi (0.20 +/- 0.10 vs. 24.43 +/- 2.20%, P less than 0.001) and a higher TRPi/GFR (106 +/- 2 vs. 80 +/- 2 micrograms/min, P less than 0.01) compared with PTH infusion during hypercapnia. Urinary adenosine 3',5'-cyclic monophosphate (cAMP) excretion was similar between the groups. During hypercapnia, when the extracellular acidemia was neutralized, the phosphaturic action of PTH persisted. These studies offer direct evidence that in chronically PTX, dietary Pi-deprived rats, the phosphaturic action of PTH is restored by hypercapnia per se. This effect appears to be independent of extracellular acidemia, changes in the plasma Pi and calcium, urinary pH and Na and cAMP excretion.

scholarly journals Age and renal prostaglandin inhibition during exercise and heat stress

1999 ◽  
Vol 86 (6) ◽  
pp. 1936-1943 ◽  
Author(s):  
W. B. Farquhar ◽  
W. L. Kenney
Keyword(s):  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Renal Blood Flow ◽  
Filtration Rate ◽  
Acute Exercise ◽  
Free Water ◽  
Placebo Control ◽  
Free Water Clearance ◽  
Urine Production

Aging is associated with a number of physiological changes that may cause the kidney to rely to a greater extent on vasodilatory PGs for normal functioning. Acute exercise has been shown to cause renal vasoconstriction that may be partially buffered by vasodilatory PGs. To determine the relative importance of renal PGs during exercise in older adults, we compared the renal effects of the PG inhibitor ibuprofen (1.2 g/day for 3 days) vs. a placebo control in a cohort of eight younger (24 ± 2 yr) and eight older (64 ± 2 yr) women during treadmill exercise (∼57% maximal oxygen consumption) in the heat (36°C). This over-the-counter dose of ibuprofen reduced renal PG (i.e., PGE2) excretion by 47% ( P < 0.05). Acute exercise in the heat caused dramatic decreases in glomerular filtration rate, renal blood flow, and sodium excretion in both age groups. PG inhibition was associated with greater decreases in urine production and free water clearance ( P < 0.05). There were no drug-related declines in glomerular filtration rate or renal blood flow. We conclude that PG inhibition has only modest effects on renal function during exercise. Also, the lack of hemodynamic changes with PG inhibition indicates that healthy well-hydrated older women are not in a renal PG-dependent state.

Cyclosporine-induced changes in glomerular filtration rate and urea excretion

1990 ◽  
Vol 88 (5) ◽  
pp. 497-502 ◽  
Author(s):  
David A. Laskow ◽  
John J. Curtis ◽  
Robert G. Luke ◽  
Bruce A. Julian ◽  
Patsy Jones ◽  
...  
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Urea Excretion ◽  
Induced Changes

Determinants of the Renal Clearance of Exogenous Lithium in a Large Sample of a White Male Working Population

1993 ◽  
Vol 85 (4) ◽  
pp. 479-485 ◽  
Author(s):  
Francesco P. Cappuccio ◽  
Pasquale Strazzullo
Keyword(s):  
Body Mass Index ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Renal Clearance ◽  
Filtration Rate ◽  
Renal Excretion ◽  
Fractional Excretion ◽  
Working Population ◽  
Proximal Tubular ◽  
Sodium Handling

1. The associations between the renal clearance of ingested lithium (used as a marker of renal proximal tubular sodium handling) and a number of biological variables have been investigated in an unselected sample of 592 healthy and untreated white men (aged 21–68 years) under their usual living conditions and drawn from a population at work. 2. Renal excretion of lithium was expressed both as clearance of lithium and as fractional excretion of lithium, i.e. normalized for unit of glomerular filtrate. 3. Clearance of lithium was positively associated with a number of anthropometric variables such as weight (r = 0.215; P <0.001), height (r = 0.212; P <0.001), body mass index (r = 0.122; P <0.01) and body surface area (r = 0.244; P <0.001). However, when expressed as fractional excretion of lithium many of these associations were lost or tended to be negative (weight, r = −0.107, P <0.01; body mass index, r = −0.119, P <0.01), greatly depending on the strong relationship between body size and/or mass and glomerular filtration rate. The associations between clearance of lithium and other renal variables reflected, in part, a spurious association mediated by the common relationship with glomerular filtration rate. However, when expressed as fractional excretion of lithium, only some associations were apparent (fractional excretion of sodium, r = 0.256, P <0.001; fractional excretion of uric acid, r = 0.336; P <0.001), probably indicating some plausible biological relationships. These results were confirmed by analysis of co-variance by quintiles of clearance of lithium and fractional excretion of lithium. 4. The results of the present study show that the renal excretion of ingested lithium (an approximate index of proximal tubular sodium handling in man) could be used in an epidemiological setting. However, the use of the fractional excretion of lithium rather than the clearance of lithium as such would be advisable to remove the confounding effects of age and anthropometry, at least in a white middle-aged male working population.

Supersensitivity to norepinephrine in chronically denervated kidneys: evidence for a postsynaptic effect

1987 ◽  
Vol 65 (11) ◽  
pp. 2219-2224 ◽  
Author(s):  
J. Krayacich ◽  
R. L. Kline ◽  
P. F. Mercer
Keyword(s):  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Renal Blood Flow ◽  
Sodium Excretion ◽  
Filtration Rate ◽  
Fractional Excretion ◽  
Urine Flow ◽  
Fractional Excretion Of Sodium ◽  
Infusion Of Norepinephrine

Denervation supersensitivity in chronically denervated kidneys increases renal responsiveness to increased plasma levels of norepinephrine. To determine whether this effect is caused by presynaptic (i.e., loss of uptake) or postsynaptic changes, we studied the effect of continuous infusion of norepinephrine (330 ng/min, i.v.) and methoxamine (4 μg/min, i.v.), an α1 adrenergic agonist that is not taken up by nerve terminals, on renal function of innervated and denervated kidneys. Ganglionic blockade was used to eliminate reflex adjustments in the innervated kidney and mean arterial pressure was maintained at preganglionic blockade levels by an infusion of arginine vasopressin. With renal perfusion pressure controlled there was a significantly greater decrease in renal blood flow (−67 ± 9 vs. −33 ± 8%), glomerular filtration rate (−60 ± 9 vs. −7 ± 20%), urine flow (−61 ± 7 vs. −24 ± 11%), sodium excretion (−51 ± 15 vs. −32 ± 21%), and fractional excretion of sodium (−50 ± 9 vs. −25 ± 15%) from the denervated kidneys compared with the innervated kidneys during the infusion of norepinephrine. During the infusion of methoxamine there was a significantly greater decrease from the denervated compared with the innervated kidneys in renal blood flow (−54 ± 10 vs. −30 ± 14%), glomerular filtration rate (−51 ± 11 vs. −19 ± 17%), urine flow (−55 ± 10 vs. −39 ± 10%), sodium excretion (−70 ± 9 vs. −59 ± 11%), and fractional excretion of sodium (−53 ± 10 vs. −41 ± 10%). These results suggest that vascular and tubular supersensitivity to norepinephrine in chronically denervated kidneys is due to postsynaptic changes involving α1-adrenergic receptors.

scholarly journals Observations on some renal function indices in dogs under ketamine-xylazine anaesthesia

2014 ◽  
Vol 12 (2) ◽  
pp. 47-51
Author(s):  
ES Ajibola ◽  
SA Rahman ◽  
KT Biobaku ◽  
N Okwelum ◽  
JA Oyewusi ◽  
...  
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Fractional Excretion ◽  
Sodium Concentration ◽  
Plasma Sodium ◽  
Treatment Groups ◽  
Plasma Sodium Concentration ◽  
Sodium Clearance

This study was done to evaluate the effect of an increased dose of ketamine on some renal function indices of Ketamine−Xylazine anaesthetised dogs. Five adult female mongrel dogs assigned to two different treatment groups in a randomized cross over design were used for this study. Each of the dogs received either 10mg/kg or 20mg/kg ketamine at a week interval. The mean glomerular filtration rate (GFR) of creatinine, absolute and fractional excretion of sodium (UNaV, FENa), urine flow rate (UFR), and plasma sodium clearance were all found to be insignificantly increased in dogs that received the higher dose regime of ketamine. All the dogs in the two treatment groups exhibited levels of glycosuria and hyposthenuria. When plasma sodium concentration of dogs treated with 10mg/kg was correlated with UNaV it was found to be significant and strong (P < 0.05; r =0.86). It was however strong but insignificant with sodium clearance (P>0.05; r = 0.82) and creatinine clearance (P> 0.05; r = 0.39). At 20mg/kg, the UNaV, sodium clearance and glomerular filtration rate all correlated weakly and insignificantly with plasma sodium concentration. The enhanced diuresis and natriuresis observed in the two treatment groups could be attributed to the effect of xylazine on either the alpha-2 adrenoceptor of the brain or those on the tubules of the kidney. These effects of xylazine could not be reversed by attempting to competitively antagonize it with a 100% increase in ketamine dose.Keywords: Diuresis, GFR fractional excretion, Ketamine, Natriuresis, xylazine

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