Ammonia production by individual segments of the rat nephron

David Good, M. B. Burg

Research output: Contribution to journalArticle

79 Citations (Scopus)

Abstract

Ammonia production was measured directly in 10 segments of the rat nephron to determine the relative importance of the segments as sites of renal ammonia production. Tubules were microdissected from normal rats and rats drinking 0.28 M NH4Cl or 0.28 M NaHCO3 for 3-8 d. The segments were incubated in vitro with and without 2 mM glutamine. Ammonia concentrations in the incubation fluid were measured by microfluorometry to determine ammonia production rates. All segments produced ammonia from glutamine. In normal rats, production with glutamine was highest (>5 pmol/min per mm) in the proximal convoluted (S-1), proximal straight (S-3), and distal convoluted tubules, and lowest (≤2) in cortical and medullary collecting ducts and thin descending limbs. Metabolic acidosis increased production by 60% in the S-1 segment of the proximal convoluted tubule and by 150% in the S-2 segment of the proximal straight tubule without significant effect in any other segment. Bicarbonate loading decreased production by S-1 but had no effect on S-2 or S-3. Thus, acid-base changes altered production only in specific segments of the proximal tubule. We infer that the bulk of ammonia production occurs in the proximal tubules and that production by collecting ducts can account for only a few percent of renal ammonia production and excretion in the rat.

Original languageEnglish
Pages (from-to)602-610
Number of pages9
JournalJournal of Clinical Investigation
Volume73
Issue number3
StatePublished - 1984
Externally publishedYes

Fingerprint

Nephrons
Ammonia
Glutamine
Cytophotometry
Kidney
Bicarbonates
Acidosis
Drinking
Extremities
Acids

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Ammonia production by individual segments of the rat nephron. / Good, David; Burg, M. B.

In: Journal of Clinical Investigation, Vol. 73, No. 3, 1984, p. 602-610.

Research output: Contribution to journalArticle

@article{f164e8a7fd184bcd9ec3c7c362cd7c1e,
title = "Ammonia production by individual segments of the rat nephron",
abstract = "Ammonia production was measured directly in 10 segments of the rat nephron to determine the relative importance of the segments as sites of renal ammonia production. Tubules were microdissected from normal rats and rats drinking 0.28 M NH4Cl or 0.28 M NaHCO3 for 3-8 d. The segments were incubated in vitro with and without 2 mM glutamine. Ammonia concentrations in the incubation fluid were measured by microfluorometry to determine ammonia production rates. All segments produced ammonia from glutamine. In normal rats, production with glutamine was highest (>5 pmol/min per mm) in the proximal convoluted (S-1), proximal straight (S-3), and distal convoluted tubules, and lowest (≤2) in cortical and medullary collecting ducts and thin descending limbs. Metabolic acidosis increased production by 60{\%} in the S-1 segment of the proximal convoluted tubule and by 150{\%} in the S-2 segment of the proximal straight tubule without significant effect in any other segment. Bicarbonate loading decreased production by S-1 but had no effect on S-2 or S-3. Thus, acid-base changes altered production only in specific segments of the proximal tubule. We infer that the bulk of ammonia production occurs in the proximal tubules and that production by collecting ducts can account for only a few percent of renal ammonia production and excretion in the rat.",
author = "David Good and Burg, {M. B.}",
year = "1984",
language = "English",
volume = "73",
pages = "602--610",
journal = "Journal of Clinical Investigation",
issn = "0021-9738",
publisher = "The American Society for Clinical Investigation",
number = "3",

}

TY - JOUR

T1 - Ammonia production by individual segments of the rat nephron

AU - Good, David

AU - Burg, M. B.

PY - 1984

Y1 - 1984

N2 - Ammonia production was measured directly in 10 segments of the rat nephron to determine the relative importance of the segments as sites of renal ammonia production. Tubules were microdissected from normal rats and rats drinking 0.28 M NH4Cl or 0.28 M NaHCO3 for 3-8 d. The segments were incubated in vitro with and without 2 mM glutamine. Ammonia concentrations in the incubation fluid were measured by microfluorometry to determine ammonia production rates. All segments produced ammonia from glutamine. In normal rats, production with glutamine was highest (>5 pmol/min per mm) in the proximal convoluted (S-1), proximal straight (S-3), and distal convoluted tubules, and lowest (≤2) in cortical and medullary collecting ducts and thin descending limbs. Metabolic acidosis increased production by 60% in the S-1 segment of the proximal convoluted tubule and by 150% in the S-2 segment of the proximal straight tubule without significant effect in any other segment. Bicarbonate loading decreased production by S-1 but had no effect on S-2 or S-3. Thus, acid-base changes altered production only in specific segments of the proximal tubule. We infer that the bulk of ammonia production occurs in the proximal tubules and that production by collecting ducts can account for only a few percent of renal ammonia production and excretion in the rat.

AB - Ammonia production was measured directly in 10 segments of the rat nephron to determine the relative importance of the segments as sites of renal ammonia production. Tubules were microdissected from normal rats and rats drinking 0.28 M NH4Cl or 0.28 M NaHCO3 for 3-8 d. The segments were incubated in vitro with and without 2 mM glutamine. Ammonia concentrations in the incubation fluid were measured by microfluorometry to determine ammonia production rates. All segments produced ammonia from glutamine. In normal rats, production with glutamine was highest (>5 pmol/min per mm) in the proximal convoluted (S-1), proximal straight (S-3), and distal convoluted tubules, and lowest (≤2) in cortical and medullary collecting ducts and thin descending limbs. Metabolic acidosis increased production by 60% in the S-1 segment of the proximal convoluted tubule and by 150% in the S-2 segment of the proximal straight tubule without significant effect in any other segment. Bicarbonate loading decreased production by S-1 but had no effect on S-2 or S-3. Thus, acid-base changes altered production only in specific segments of the proximal tubule. We infer that the bulk of ammonia production occurs in the proximal tubules and that production by collecting ducts can account for only a few percent of renal ammonia production and excretion in the rat.

UR - http://www.scopus.com/inward/record.url?scp=0021334123&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0021334123&partnerID=8YFLogxK

M3 - Article

C2 - 6323523

AN - SCOPUS:0021334123

VL - 73

SP - 602

EP - 610

JO - Journal of Clinical Investigation

JF - Journal of Clinical Investigation

SN - 0021-9738

IS - 3

ER -