Viellissement réussi chez le rat
Christelle Veyrat-Durebex
Abstract
Aging is associated with important physiological modifications but origins are still greatly discussed. It could be related with endocrine alterations as the decline of somatotroph function that lead to a decrease of growth hormone (GH) release with age. However, feeding patterns seem to play an important role on this process. Benefic effects of caloric restriction (CR) on rat longevity are reported in the literature and recent studies led on a particular strain of rats, the Lou/C strain, have showed a new model of successful aging. Those rats eat twice less and have a longer life expectancy that more usual strains of laboratory rats, and do not develop obesity with age. In these both case of CR, induced or spontaneous, benefic effects on somatotroph function have been reported. It maintained the GH release but also prevent from alterations observed in old rats on pituitary binding sites of the growth hormone-releasing factor. Then, development of new strategies of nutritional state control could be the choice over the hormonal substitution therapies during aging.