The Effects of Urea Infusion on Glomerular Filtration Rate and Renal Plasma Flow in Sheep Fed Low and High Protein Diets

Ergene, Neyhan; Pickering, E.C.

doi:10.1113/expphysiol.1978.sp002417

Cited by 9 publications

(5 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…remained virtually constant despite changes in nitrogen intake (Experiment 2). Similar results were obtained by Ergene & Pickering (1978b) following intravenous urea administration to sheep fed low protein diets. It appears that the major determinant of the increased diuresis was simply greater water intake and lower circulating ADH levels.…”

Section: Discussionsupporting

confidence: 83%

Renal Control of Plasma Urea Level in Sheep: The Diuretic Effect of Urea, Potassium and Sodium Chloride

Godwin¹,

Williams²

1984

Exp Physiol

View full text Add to dashboard Cite

Two merino ewes were fed 800 and then 1000 g of lucerne chaff per day and renal responses and extracellular fluid volume (E.C.F.) were determined. Urine urea nitrogen, glomerular filtration rate (G.F.R.), urine volume, effective renal plasma flow (E.R.P.F.) and E.C.F. increased in both animals with the greater nitrogen intake. In a second experiment, five merino wethers and four merino ewes were infused intraruminally with increasing quantities of urea, whilst being fed a mainly roughage ration, and the above parameters were determined. No significant changes in G.F.R., E.R.P.F. or E.C.F. were noted. Urinary excretion maintained a linear response to nitrogen input until 20·6 g of urea nitrogen per day were infused. At this level of infusion, an increased fractional reabsorption of urea resulted in a large increase in plasma urea concentration, but when 500 mmol of NaCl or KCl were added to the infusate, urine urea nitrogen excretion increased from 10·4 to 11·4 and 11·9 g/d respectively and plasma urea concentration decreased from 68·0 to 35·2 and 37·3 mg nitrogen/100 ml. Urea clearance virtually trebled with both electrolyte infusions and E.C.F. and G.F.R. increased by aproximately 10 and 25% respectively. It is concluded that urea alone has limited diuretic ability and that the increased electrolyte content of higher protein dry roughage diets aids urine urea excretion by increasing G.F.R., and the urine flow rate by an osmotic diuretic effect.

show abstract

Section: Discussionsupporting

confidence: 83%

Renal Control of Plasma Urea Level in Sheep: The Diuretic Effect of Urea, Potassium and Sodium Chloride

Godwin¹,

Williams²

1984

Exp Physiol

View full text Add to dashboard Cite

show abstract

“…Renal plasma flow (RPF) that has been noted to decrease on low protein diet in sheep accompaning the decrease of the GFR (Gans and Mercer, 1962;Rabinowitz et al 1973;Ergene and Pickering 1978 b), was not measured in the present study. The changes in the GFR are presumably associated with changes in the RPF, but the relation is not unconditional since, according to the study of Ergene and Pickering (1978 b), an elevated intake of sodium chloride on low protein diet may increase the RPF without affecting the GFR.…”

mentioning

confidence: 62%

Renal responses of reindeer to high and low protein diet and sodium supplement

Valtonen

1979

AFSci

View full text Add to dashboard Cite

The effects of reducing dietary nitrogen and increasing sodium chloride intake on renal function were studied in reindeer in order so elucidate the extent of urea conservation and solute excretion by the reindeer kidney. The fall in plasma urea concentration and urea excretion on the low protein diet was accompanied by a significant reduction in the glomerular filtration rate (GFR) and urine osmolality. The fraction of filtered urea reabsorbed increased. However, the contribution of the fall of the GFR to restriction of urinary losses of urea was far more significant than the increase in fractional urea reabsorption. The increase in sodium chloride intake reflected in icreased urinary sodium excretion, inducing a rise in urine osmolality on the low protein diet. Increased excretion of sodium was accompanied by decreased urea excretion. This interdependence of urea and sodium in urine excretion was particularly pronounced during the mating season in the autumn, when prominent retention of electrolytes and water was observed. On low protein diet, when reindeer were exposed to cold, the energy intake proved insufficient. The use of body protein as energy source resulted in increased plasma urea values. The fractional reabsorption of urea decreased, but the GFR stayed low. The GFR seems to be unaffected by plasma urea concentrations but is in some way regulated by the intake of dietary protein. Also on lichen diet the intake was not sufficient to satisfy the energy requirements and the plasma urea concentrations increased. The urea excretion was still low due to a decreased GFR. The high moisture content of lichen caused an increase in the urine water excretion, but no increase occured in the solute excretion. The rumen ammonia concentrations correlated significantly with the plasma urea concentrations, showing that urea is readily returned to the rumen in reindeer. The restriction of urea excretion on low protein intake contributes to the nitrogen economy and in reindeer it is brought about by a marked decrease in the GFR together with an increase in the urea reabsorption.

show abstract

“…It is known that protein intake leads to renal hyper-perfusion and plasma hyperfiltration in the renal glomerulus, so that it can enhance urine formation [25,53]. The possibility of higher plasma filtration in the kidneys of animals after feeding and protein intake can explain the filtered tubular load of creatinine and PD, thus increasing their urinary excretion [24,[53][54][55][56].…”

Section: Discussionmentioning

confidence: 99%

Creatinine as a Urinary Marker of the Purine Derivatives Excretion in Urine Spot Samples of Lambs Fed Peach Palm Meal

Pereira

Carvalho

et al. 2022

Animals

View full text Add to dashboard Cite

The objective was to evaluate the influence of diets on lambs using different levels of peach palm meal as a replacement for maize (0, 10, 40, 60, and 85% of diet dry matter) on the endogenous creatinine clearance (CC), urine concentration ratio of purine derivatives to creatinine (PDC index), and daily creatinine excretion (DCE) as a marker to estimate purine derivatives (PD) excretion from urinary spot samples collected at different time points (4, 8, 12, 16, 20, 24 h after morning feeding) compared to 24-h total urine collection. The measured parameters were voluntary intake, urinary volume, CC, DCE, the concentration of plasma creatinine, and PD and purine derivatives’ excretion (PDE). Five lambs were allocated to metabolic cages and distributed in a 5 × 5 Latin square. Urine collection was taken daily on days 16 to 19 of each experimental period. The inclusion of peach palm meal linearly reduced the intake of dry matter (g kg BW−0.75, p = 0.005), crude protein (g kg BW−0.75, p = 0.010), metabolizable energy (MJ kg BW−0.75, p = 0.010) and CC (p < 0.0001). It also quadratically affected the urinary volume (p = 0.008) and DCE (p = 0.004). There was a linear decrease for PDC index (p = 0.032) and PDE (p < 0.0001) measured in the 24-h total urine with peach palm meal levels. The different times of spot urine sampling did not affect (p > 0.05) the PDC index and PDE. Peach palm meal decreases the CC thereby compromising the use of a mean value of DCE as a PDE marker in spot urine samples. There is greater accuracy when using different values of DCE obtained for each diet as markers for the PDE in spot urine samples. Unconventional foodstuffs of low palatability affecting the voluntary intake of feed change the renal function.

show abstract

The Effects of Urea Infusion on Glomerular Filtration Rate and Renal Plasma Flow in Sheep Fed Low and High Protein Diets

Cited by 9 publications

References 4 publications

Renal Control of Plasma Urea Level in Sheep: The Diuretic Effect of Urea, Potassium and Sodium Chloride

Renal Control of Plasma Urea Level in Sheep: The Diuretic Effect of Urea, Potassium and Sodium Chloride

Renal responses of reindeer to high and low protein diet and sodium supplement

Creatinine as a Urinary Marker of the Purine Derivatives Excretion in Urine Spot Samples of Lambs Fed Peach Palm Meal

Contact Info

Product

Resources

About