Regulation of renal sodium calcium exchange by PTH: Alteration with age

Journal Article · Thu Mar 01 00:00:00 EST 1990 · Environmental Health Perspectives; (United States)

DOI:https://doi.org/10.1289/ehp.9084137· OSTI ID:5451387

Liang, C T; Hanai, Hiroyuki; Ishida, Makoto; Cheng, L; Sacktor, Bertram ^[1]

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

Parathyroid hormone, when incubated with renal cells acting in vivo and in vitro, increased Na{sup +}/Ca{sup 2+} exchange activity. The effect of parathyroid hormone was specific for biologically active analogs and could be mimicked by cAMP and forskolin. Parathyroid hormone-sensitive Na{sup +}/Ca{sup 2+} exchange activity was markedly blunted in cells from senescent rats. Parathyroid hormone-stimulated adenylate cyclase was also decreased in aging. In contrast, forskolin-stimulated Na{sup +}-dependent {sup 45}Ca{sup 2+} efflux and adenylate cyclase did not change with senescence. Decrease of PTH binding sites was observed in cells from old rats. Further, cells from 24-month-old rats had decreased Gs and Gi proteins, as detected by ADP-ribosylation. Since serum iPTH level was elevated in the old rat and could contribute to the desensitization to PTH, the authors tested this hypothesis by comparing sham-operated and PTX animals. In conclusion, the results suggested that the age related blunting in responses of renal cells to PTH was due, at least in part, to the elevated serum iPTH level in old rats.

• OSTI ID: 5451387
• Journal Information: Environmental Health Perspectives; (United States), Vol. 84; ISSN 0091-6765
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
CALCIUM 45
MEMBRANE TRANSPORT
PARATHORMONE
BIOLOGICAL EFFECTS
AGE DEPENDENCE
BLOOD SERUM
CYCLASES
KIDNEYS
PHOSPHORUS 32
RATS
SODIUM COMPOUNDS
ALKALI METAL COMPOUNDS
ALKALINE EARTH ISOTOPES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CALCIUM ISOTOPES
DAYS LIVING RADIOISOTOPES
ENZYMES
EVEN-ODD NUCLEI
HORMONES
INTERMEDIATE MASS NUCLEI
ISOTOPES
LIGHT NUCLEI
LYASES
MAMMALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PHOSPHORUS ISOTOPES
PROTEINS
RADIOISOTOPES
RODENTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques