Micropuncture study of composition of proximal and distal tubular fluid in rat kidney

KJ Ullrich, B Schmidt-Nielsen… - American Journal …, 1963 - journals.physiology.org
KJ Ullrich, B Schmidt-Nielsen, R O'Dell, G Pehling, CW Gottschalk, WE Lassiter, M Mylle
American Journal of Physiology-Legacy Content, 1963journals.physiology.org
Fluid was collected by micropuncture from proximal and distal convolutions of anesthetized
rats and analyzed for inulin, sodium, urea, and total osmotically active solute. The proximal
fluid/plasma (F/P) sodium ratio was not significantly different from unity in antidiuretic
animals, but was as low as 0.78 during mannitol diuresis. The distal F/P sodium ratio
averaged 0.62 in antidiuresis, and 0.24 during osmotic diuresis. The data are interpreted to
indicate active sodium transport by both proximal and distal convolutions. The F/P ratios for …
Fluid was collected by micropuncture from proximal and distal convolutions of anesthetized rats and analyzed for inulin, sodium, urea, and total osmotically active solute. The proximal fluid/plasma (F/P) sodium ratio was not significantly different from unity in antidiuretic animals, but was as low as 0.78 during mannitol diuresis. The distal F/P sodium ratio averaged 0.62 in antidiuresis, and 0.24 during osmotic diuresis. The data are interpreted to indicate active sodium transport by both proximal and distal convolutions. The F/P ratios for inulin, urea, and total osmotically active solute are in general agreement with previous studies.
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