Renal adaptation to metabolic acidosis in senescent rats

Journal Article · Thu Dec 01 00:00:00 EST 1988 · American Journal of Physiology; (USA)

OSTI ID:6036798

Prasad, R; Kinsella, J L; Sacktor, B ^[1]

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1. National Institutes of Health, Baltimore, MD (USA)

In this study, the authors compared results obtained in senescent rats with young rats given an equivalent acid load. They examined the renal changes by giving equivalent acid loads for 48 h to both 6- and 24-mo-old rats. The basal excretion of ammonium was the same in both groups, whereas titratable acids, phosphate, and Ca{sup 2+} excretions were increased in the senescent animal. After administration of the acid load, ammonium, phosphate, Ca{sup 2+}, and titratable acid excretions increased in both age groups, but there were greater absolute increases in ammonium and titratable acid excretions in the young rats. The total acid excreted by the 24-mo rats was reduced 50 (day 1) and 25% (day 2) compared with the young rats, which was reflected by the more severe acidosis in those animals. The portion of total acid excreted as titratable acids in senescent animals was also increased during acidosis when compared with the young animals. In isolated proximal tubule brush-border membrane vesicles, acidosis increased Na{sup +}-H{sup +} exchange and decreased Na{sup +}-dependent phosphate transport in both age groups. They also found that the basal activity of the Na{sup +}-H{sup +} exchanger was not changed with age but the Na{sup +} dependent phosphate transporter was less in the 24-mo rat. The results suggest that physiological regulation of these renal processes remains intact in the aged rat but the responses may be reduced or delayed in the senescent animal.

• OSTI ID: 6036798
• Journal Information: American Journal of Physiology; (USA), Vol. 255:6; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
KIDNEYS
BIOLOGICAL ADAPTATION
LABELLED COMPOUNDS
UPTAKE
MEMBRANE TRANSPORT
AGE DEPENDENCE
SODIUM 22
ACIDIFICATION
AGED ADULTS
EXCRETION
GLUCOSE
METABOLIC DISEASES
PHOSPHATES
PHOSPHORUS 32
RATS
ALDEHYDES
ALKALI METAL ISOTOPES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
CARBOHYDRATES
CLEARANCE
DAYS LIVING RADIOISOTOPES
DISEASES
HEXOSES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIGHT NUCLEI
MAMMALS
MONOSACCHARIDES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
PHOSPHORUS ISOTOPES
RADIOISOTOPES
RODENTS
SACCHARIDES
SODIUM ISOTOPES
VERTEBRATES
YEARS LIVING RADIOISOTOPES
551001* - Physiological Systems- Tracer Techniques