Two papers describe regimens that protect muscle mitochondria against the ravages of time: Sethumadhavan and Chinnakannu show that a combination of carnitine and lipoic acid alleviate age-related decline in cardiac muscle respiratory activity. Meanwhile, Baker et al. demonstrate that calorie restriction preserves the oxidative capacity, though not the levels of respiratory proteins, in skeletal muscle mitochondria.
Dietary restriction was also found to delay the increase of T-kininogen (Acuña-Castillo et al.), an immune suppressant previously reported to be a biomarker of aging in the rat, as well as the age-related loss of muscle mass termed sarcopenia (Edström et al.).
Continuing with the biomarker theme, the Edström paper also shows the protein profile of sarcopenia (age-related decline in muscle mass) to be distinct from that of acute injury-induced muscle atrophy. In other words, in muscle at least, we can begin to distinguish between aging per se and simple “wear and tear” via a molecular measurement.
It’s a good week in the field…at least, if you happen to be a rat.
(Reminds me of a story Bruce Ames tells during most talks: He told his son, “We’ve come up with a way to turn old rats into young rats!” His son replied, “Let me know when you’re able to turn old people into young rats.”)