Biological aging as a diffusion phenomenon

The general cross-linkage theory of biological aging is pointed out to consist of two distinct branches: mutation theory and diffusion theory. Only diffusion theory is considered though. The diffusion theory of aging is expressed as a sum of terms. One of those terms is expressed in differential equation form, and the complete mathematical solution to it obtained under certain limiting assumptions. An approximation to the complete solution is applied to four distinct cases—(1) rat tendon collagen, (2) cellular waste products in humans, (3) collagen in humans and (4) lipofuscins in the human myocardium. Only cases (1) and (4) are compared to experimental data. Case (1) shows excellent agreement, while case (4) displays discrepancies which suggest that the lipofuscins have an age pigment precursor.