[Cyclic feeding regime--a new model for experimental gerontology]

The influence of specific cyclic feeding regime (CFR) providing 30% loss of body weight for 14 days and 14 days recovery period followed by the standard feeding diet in the course of 30 days, on rat life span was investigated. It has been shown that young and old animals differed in intensity loss and recovery of body weight after three cycles CFR. The mass of liver changes cyclically as well as body weight. It was found that the content of glucose and protein in serum was cyclically changed only in the first cycle of CFR; during the second cycle of the same feeding regime a completely different trend of these parameters was observed. Such nature of the dynamics on the same type of repetitive exposure indicates change in adaptation strategies. This indicates the usage of alternative metabolic pathways that provide survival in extreme conditions. Each subsequent cycle of weight loss-restoration differed from the previous one and had a pronounced age-related character. Animals that have successfully passed three consecutive CFR beginning from 19-months of age had longer life span as compared with the control animals group. CFR can be used as a new model in gerontology providing increased life when transferred on a diet not only young but also old animals.