Figure 1. Heterochronic parabiosis reverses age-related cardiac hypertrophy.

(A) Experimental scheme. Pairs of young isochronic, heterochronic and old isochronic parabiotic mice were generated. 4 weeks after parabiosis surgery mice were euthanized and tissues harvested for analysis.

(B) Reduced heart size in old mice exposed to a young circulation for 4 weeks. Trichrome stained cross-sections at mid-ventricle.

(C). Graph representing the heart weight / tibia length ratio after 4 weeks of parabiosis. The heart weight to tibia length ratio was significantly lower in old mice exposed to a young circulation (O-HP) compared to old mice exposed to an old circulation (O-IP) for 4 weeks and to old unpaired mice (O). No significant difference was observed when comparing old isochronic to old unpaired mice or when comparing any of the young groups.

Data shown as mean ± s.e.m. See also Figure S1.