A further test of the equation of lifespan by C. elegans: Effective activation energy for aging and lifespan

We previously proposed a rate theory of chemical reaction as well as a lifespan equation derived by a stochastic fluctuation theory. Both were applied to biodemographic data by C. elegans to quantitatively explain that respiratory activity declines exponentially with age and that it has a physiological decline rate and a finite value (threshold) in advanced age. In this work, using the poikilothermic nature of Caenorhabditis elegans, we demonstrate the further validity of the rate theory of chemical reaction as well as the lifespan equation by changing two methods. First, to test the appropriateness of the lifespan equation from another aspect, lifespan assays were conducted by varying the time interval of observation employing the egl-1 mutant. The results indicate that, as the time interval is reduced, mortality rates gradually approach the force of mortality expected from the fitting equation of the survival curve. Second, based on the dependence of lifespan on the temperature of the culture, the physiological decline rate, and the onset of biodemographic aging, we show that the effective activation energy or energy barrier for aging and lifespan may be closely related to the standard free-energy change of ATP or ADP for a wild type and some lifespan-related mutants of C. elegans.

Research Highlights
► The further validity of the lifespan equation is demonstrated.
► Mortality rates approach the force of mortality with reducing the time interval.
► The effective activation energy or energy barrier for lifespan is estimated.
► Energy barrier is closely related to the standard free-energy change of ATP.
► Aging is the process of individuation.