Renal adaptation to metabolic acidosis in senescent rats

Journal Article · Thu Dec 01 04:00:00 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), Journal Name: American Journal of Physiology; (USA) Vol. 255:6; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

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