The effect of aging on endoneurial blood flow, hyperemic response and oxygen-free radicals in rat sciatic nerve.
Electrophysiologic abnormalities and reduced energy metabolic rate develop in aging nerves. We investigated the effects of aging on nerve blood flow (NBF) in Fischer rats aged 2, 12, 24 and 30 months. NBF regressed negatively with increasing age and this decline was associated with an increase in nerve vascular resistance. Twenty minutes of nerve stimulation resulted in an increase in blood flow by about 50% in adult animals and did not decline with increasing age. As indices of oxygen free radical activity, we measured conjugated dienes, hydroperoxides, and norepinephrine from 2 to 30 months. There was a gradual decline with increasing age of all indices. We conclude that NGF declines with aging due to reduced microvascular caliber. These vessels retain their hyperemic response and oxygen free radical activity is less with increasing age.
Kihara
M
M
Department of Neurology, Mayo Foundation, Rochester, MN 55905.
Nickander
K K
KK
Low
P A
PA
D000375:Aging; D000818:Animals; D001775:Blood Circulation; D004558:Electric Stimulation / Q000379:methods; D004594:Electrophysiology / Q000379:methods; D005609:Free Radicals; D008054:Lipid Peroxides / Q000032:analysis*; D008315:Malondialdehyde; D009638:Norepinephrine / Q000032:analysis; D051381:Rats; D012039:Regional Blood Flow; D012044:Regression Analysis; D012584:Sciatic Nerve / Q000098:blood supply / Q000254:growth & development / Q000502:physiology*; D014655:Vascular Resistance
D005609:Free Radicals; D008054:Lipid Peroxides; D008315:Malondialdehyde; D009638:Norepinephrine