Mechanisms of Prolonged Longevity: Mutants, Knock-Outs, and Caloric Restriction

Interestingness: 4

By A Bartke and D Turyn, in the Journal of Anti-Aging Medicine, September 2001, 4(3): 197-203. doi:10.1089/109454501753249966.

Short paper mainly describing the Snell and Ames dwarf mice, some other dwarf mouse (lit/lit), the growth hormone receptor knock-out mouse (GHR-KO), with a small bit comparing them to calorie-restricted mouse.  Life span expansion of those is 55%, 25%, 45%, and (from another source since I couldn't see the graph), 30% respectively.

The important bit is a table comparing a lot of attributes across them. Attributes shown: plasma insulin, plasma glucose, sensitivity to insulin, plasma growth hormone, plasma IGF-1, body size, plasma thyroid hormone levels, body core temperature, sexual maturation, fertility, plasma corticosterone and percentage body fat.  In all versions of the mice, most of the levels move in the same direction (glucose down, insulin sensitivity up, GH, IGF-1 and body size down, delayed fertility, reduced body temperature).  Main difference between CR mice and the others is that the level of corticosterone are up in CR, while they stay at normal levels in the others.  Also, body fat is down in CR, normal in the others. 

The common elements are more likely to be important for life extension than the ones which are different, although the paper mentions that the raised corticosterone is considered to be a very important part of the effect of CR.