Basic principle of the lifespan in the nematode C. elegans.
We present a biophysical model based on the principles of fluctuation and regulation to explain the effect of stochastics on survival. The model is a good fit for the survivorship and mortality rates observed in the nematode Caenorhabditis elegans. A parameter included in the theory, which is called the fluctuation constant, correlates well with a change (or declining rate) of respiration with age, which we term the physiological decline rate. The square of the physiological decline rate is proportional to the reciprocal of the fluctuation constant as revealed in a diffusion equation. In addition, the maximum and mean life spans are proportional to the reciprocal of the decline rate. The framework involved in the fluctuation theory is compatible with the existence of a regulatory system such as that acting in the insulin/insulin-like growth factor-1 (IGF-1) signaling pathway during adulthood, and that sensing, switching, and memorizing the rate of mitochondrial respiration early in life.
Shoyama
Tetsuji
T
Department of Biological Science and Technology, School of High-technology for Human Welfare, Tokai University, 317 Nishino, Numazu, Shizuoka 410-0395, Japan.
Ozaki
Takami
T
Ishii
Naoaki
N
Yokota
Shigefumi
S
Suda
Hitoshi
H
D000818:Animals; D017173:Caenorhabditis elegans / Q000378:metabolism / Q000502:physiology*; D019069:Cell Respiration; D004734:Energy Metabolism; D008136:Longevity; D008928:Mitochondria / Q000378:metabolism*; D008954:Models, Biological; D013269:Stochastic Processes; D013997:Time Factors