Effects of aging on the regulation of intracellular pH in the rat jejunum.
J Gerontol A Biol Sci Med Sci
; 51(5): B346-53, 1996 Sep.
Article
en En
| MEDLINE
| ID: mdl-8808983
Jejunal villus cells from young-adult (6 months) and senescent (24 months) male Wistar rats were studied to evaluate the effect of aging on intracellular pH (pHi) regulation. pHi was measured by quantitative fluorescence microscopy by using BCECF-AM [2',7'-bis(carboxyethyl)-5(6)-carboxy-fluorescein acetoxy methylester] under basal conditions and after inducing cytoplasmic acidification with pulsed NH4Cl. In the senescent rats, the recovery rate from the acidified levels was significantly lower than that in the young-adult rats (.208 +/- .005 vs .255 +/- .004 pH units/min). The relationship between pHi recovery and external Na+ concentration followed Michaelis-Menten type kinetics, the maximum velocity (Vmax) of alkalinization being significantly lower in the senescent rats than in the young-adult rats (.227 +/- .033 vs .297 +/- .024 pH units/min). These results indicate that the recovery of pHi from an acidic level was slower in the senescent rats, due to the reduced activity of Na+/H+ exchange as revealed by the decreased Vmax value.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Envejecimiento
/
Yeyuno
Límite:
Animals
Idioma:
En
Revista:
J Gerontol A Biol Sci Med Sci
Asunto de la revista:
GERIATRIA
Año:
1996
Tipo del documento:
Article
País de afiliación:
Japón
Pais de publicación:
Estados Unidos