The effect of various dietary restricted regimes on biochemical variables in the mouse.

Twenty-one day old and seventeen month old female mice were fed the following three dietary regimes for one or six months: 1) 24% protein ad libitum; 2) 4% protein ad libitum; or 3) 24% protein intermittently fed (diet offered for twenty-four hours on Monday and Wednesday, and for eight hours on Friday). The activities of succinoxidase, malic dehydrogenase and cholinesterase as well as the concentrations of protein and DNA were determined in livers and kidneys. Calculated on the basis of DNA, the activities of these three enzymes as well as protein content were decreased in the 4% and intermittent-fasted animals and increased in the intermittent-fed animals. The mean values of the enzymes as well as the protein content per mg. of DNA of the intermittent-fed and intermittent-fasted animals were essentially the same as that of the 24% ad libitum controls. These findings were obtained on both young-growing and adult animals. INDEX WORDS: Dietary restriction, enzymes, age, mouse, protein synthesis, genetic code use.