[Profile of the capacity for lipid synthesis in vivo in various rat tissues: effect of age].

Changes in 3H2O incorporation in vivo to lipid fractions have been studied in rats 1, 3 and 13 months old. The incorporation of tritiated water into non-saponifiable fraction showed and age-dependent decrease in liver. The values were 4.32, 2.91 and 2.56 mumol 3H2O incorporated/g wet weight of liver/hour, at 1, 3 and 13 months respectively. Similar variations could be observed in adipose tissue and in blood. The rates of lower lipogenesis increase markedly from 1 to 3 months (7.02 to 13.36 mumol 3H2O/g/h) and decrease sharply from the 3rd to 13th months (13.36 to 3.75 mumol 3H2O/g/h). The incorporation of radioactivity into blood and adipose tissue fatty acids, also decrease by age.