Mp. Schweizer et al., IN-VIVO P-31-NMR STUDIES OF AGE AND ENERGY-METABOLISM IN AN ANIMAL FLAP MODEL, Plastic and reconstructive surgery, 96(2), 1995, pp. 429-435
Changes in phosphate energy metabolism with time in a rat flap model w
ere followed noninvasively with in vivo P-31-NMR. The influence of age
on high-energy phosphate metabolites in perfused and ischemic ends of
3 x 10 cm dorsal flaps was noted from 30 minutes to 7 days after clos
ure in 6-, 12-, and 24-month-old (n = 4, 7, and 8, respectively) male
Fischer 344 rats. Phosphocreatine to inorganic phosphate ratios showed
younger animals exhibiting significant returns to preinjury energy st
atus in 2- and 3-mm ischemic layers. This behavior, 24 to 72 hours aft
er closure, coincides with neovascularization of the flap tissue. By c
ontrast, 12- and 24-month-old animals experienced statistically signif
icantly lesser high-energy rebound, developing greater necrosis in the
ischemic regions. Early intracellular pH lowering, indicative of lact
ate production, was somewhat greater in the flaps of younger animals.
The in vivo P-31-NMR methods thus provide metabolic insights into flap
behavior correlating with physiologic influences of aging.