Overall renal and tubular function during infusion of amino acids in normal man
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Overall renal and tubular function during infusion of amino acids in normal man. / Olsen, Niels Vidiendal; Hansen, J M; Ladefoged, S D; Fogh-Andersen, N; Nielsen, S L; Leyssac, Paul Peter.
In: Clinical Science, Vol. 78, No. 5, 05.1990, p. 497-501.Research output: Contribution to journal › Journal article › Research › peer-review
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T1 - Overall renal and tubular function during infusion of amino acids in normal man
AU - Olsen, Niels Vidiendal
AU - Hansen, J M
AU - Ladefoged, S D
AU - Fogh-Andersen, N
AU - Nielsen, S L
AU - Leyssac, Paul Peter
PY - 1990/5
Y1 - 1990/5
N2 - 1. Amino acids have been used to test renal reserve filtration capacity. Previous studies suggest that amino acids increase glomerular filtration rate (GFR) by reducing distal tubular flow and tubuloglomerular feedback activity. 2. Glomerular function and the renal tubular handling of sodium during infusion of amino acids was studied in 12 normal volunteers. 3. Clearance of sodium (CNa) was unchanged. Effective renal plasma flow increased slightly, but significantly, by 9% (P less than 0.05). GFR was increased by 13% (P less than 0.001). Clearance of lithium (CLi) (used as an index of proximal tubular outflow) increased by 38% (P less than 0.001). Calculated absolute proximal reabsorption (GFR-CLi) remained unchanged. Fractional proximal reabsorption [1-(CLi/GFR)] was decreased by 10% (P less than 0.001). Calculated absolute distal sodium reabsorption [(CLi-CNa) x PNa, where PNa is plasma sodium concentration] increased by 40% (P less than 0.001). Plasma renin concentration did not change significantly. 4. The results suggest that amino acids increase GFR by a primary effect on renal haemodynamics or, less likely, by reducing the signal to the tubuloglomerular feedback mechanism. The increase in proximal tubular outflow was compensated for in the distal tubules, so that the sodium excretion rate remained unchanged.
AB - 1. Amino acids have been used to test renal reserve filtration capacity. Previous studies suggest that amino acids increase glomerular filtration rate (GFR) by reducing distal tubular flow and tubuloglomerular feedback activity. 2. Glomerular function and the renal tubular handling of sodium during infusion of amino acids was studied in 12 normal volunteers. 3. Clearance of sodium (CNa) was unchanged. Effective renal plasma flow increased slightly, but significantly, by 9% (P less than 0.05). GFR was increased by 13% (P less than 0.001). Clearance of lithium (CLi) (used as an index of proximal tubular outflow) increased by 38% (P less than 0.001). Calculated absolute proximal reabsorption (GFR-CLi) remained unchanged. Fractional proximal reabsorption [1-(CLi/GFR)] was decreased by 10% (P less than 0.001). Calculated absolute distal sodium reabsorption [(CLi-CNa) x PNa, where PNa is plasma sodium concentration] increased by 40% (P less than 0.001). Plasma renin concentration did not change significantly. 4. The results suggest that amino acids increase GFR by a primary effect on renal haemodynamics or, less likely, by reducing the signal to the tubuloglomerular feedback mechanism. The increase in proximal tubular outflow was compensated for in the distal tubules, so that the sodium excretion rate remained unchanged.
KW - Absorption
KW - Adolescent
KW - Adult
KW - Amino Acids
KW - Female
KW - Glomerular Filtration Rate
KW - Hematocrit
KW - Humans
KW - Kidney
KW - Kidney Tubules
KW - Lithium
KW - Male
KW - Middle Aged
KW - Osmolar Concentration
KW - Renal Circulation
KW - Sodium
M3 - Journal article
C2 - 2162277
VL - 78
SP - 497
EP - 501
JO - Clinical Science
JF - Clinical Science
SN - 0143-5221
IS - 5
ER -
ID: 47241040