Activities of monoamine oxidase B, Cu-Zn-dependent superoxide dismutase (SOD), and catalase, the concentration of enzyme-active ceruloplasmin, and resistance of the nerve tissue to oxidative stress were examined in spinal cord preparations from humans (n=43) died at the age of 21-92 years. Age-related activation of monoamine oxidase B was found only in thoracic segments, while age-related decrease in SOD activity was demonstrated in thoracic segments and cervical intumescence of the spinal cord. Age-related accumulation of enzyme-active ceruloplasmin was observed in all segments of the spinal cord. Activation of catalase and increased sensitivity to oxidative stress were observed in the cervical and lumbosacral intumescences. Heterotopic changes in the examined indices suggest that activity of monoamine oxidase B cannot serve as a universal factor of age-related changes in antioxidant defense in the spinal cord and its sensitivity to oxidative stress.