Food restriction slows down age-related changes in cell membrane parameters.

The effect of undernutrition on some plasma membrane parameters has been analyzed. Diet restriction was applied to female Wistar rats on every-other-day schedule (EOD), starting from the age of 3.5 months. Membrane microviscosity of splenic lymphocytes was lower in EOD rats than in the ad libitum (AL) fed ones even if one assumes a decrease of body temperature of 2 degrees C. The decrease of membrane microviscosity due to diet restriction ran parallel with the improvement of proliferative response of lymphocytes. The analysis of Arrhenius plots of 1,6-diphenyl-1,3,5-hexatriene as well as of 5'-nucleotidase activity showed a diet-dependent improvement of membrane properties also of liver plasma membranes. Diet restriction was able to partially recover the age-dependent decrease of beta-adrenoceptor density of cerebellar membranes. On the contrary, beta-adrenoceptor density of lymphocytes, which did not show any age-dependent alteration, was not influenced by diet restriction. Present results support that undernutrition exerted a protective effect on cell membranes of old animals and it was able to improve those alterations which are related to aging.