Ageing effects on sugar intestinal transport were studied by using the everted sac and the brush-border membrane vesicle techniques. Four age groups of rats were used: very young, young, adult and old animals. Net transintestinal transport of d-glucose and intracellular sugar accumulation were greater in young than in very young, adult and old rats. Net Na+ transport was high in very young and young animals and then it declined with age. In brush-border membrane vesicle experiments d-glucose overshoot was smaller in the groups of animals where net sugar transport was less. In old rats, however, the overshoot did not occur. Short-circuiting of vesicles with valinomycin showed that the driving forces for sugar accumulation, i.e. the chemical potential gradient of Na+ and the electrical potential gradient, played different roles during ageing. In very young animals the chemical potential gradient seems to be responsible for d-glucose overshoot; in young rats both gradients are important while in adult animals the electrical potential gradient represents the main driving force.
Intestinal sugar transport during ageing / C. Lindi, P. Marciani, A. Faelli, G. Esposito. - In: BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES. - ISSN 0005-2736. - 816:2(1985), pp. 411-414.
Intestinal sugar transport during ageing
C. LindiPrimo
;P. MarcianiSecondo
;A. FaelliPenultimo
;
1985
Abstract
Ageing effects on sugar intestinal transport were studied by using the everted sac and the brush-border membrane vesicle techniques. Four age groups of rats were used: very young, young, adult and old animals. Net transintestinal transport of d-glucose and intracellular sugar accumulation were greater in young than in very young, adult and old rats. Net Na+ transport was high in very young and young animals and then it declined with age. In brush-border membrane vesicle experiments d-glucose overshoot was smaller in the groups of animals where net sugar transport was less. In old rats, however, the overshoot did not occur. Short-circuiting of vesicles with valinomycin showed that the driving forces for sugar accumulation, i.e. the chemical potential gradient of Na+ and the electrical potential gradient, played different roles during ageing. In very young animals the chemical potential gradient seems to be responsible for d-glucose overshoot; in young rats both gradients are important while in adult animals the electrical potential gradient represents the main driving force.Pubblicazioni consigliate
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