X-Message-Number: 3944 From: (David Stodolsky) Subject: PBN Reversal of Brain Aging ( abstract ) Date: Thu, 2 Mar 95 19:11:09 +0100 (CET) Forward of article <> () by : From: Newsgroups: sci.life-extension Subject: PBN Reversal of Brain Aging ( abstract ) Date: Wed, 15 Feb 95 01:04:11 -0500 Carney JM Floyd RA Protection against oxidative damage to CNS by alpha-phenyl- tert-butyl nitrone (PBN) and other spin-trapping agents: a novel series of nonlipid free radical scavengers. In: J Mol Neurosci (1991) 3(1):47-57 Brain is extremely susceptible to oxidative damage. Utilizing a series of novel approaches, we have demonstrated that oxidative damage occurs during an ischemia/reperfusion insult (IRI) to brain. Thus, we have demonstrated that an IRI to Mongolian gerbil brain results in: (1) an enhanced rate of salicylate hydroxylation, implicating an increased flux of hydroxyl free radicals; (2) an enhanced flux of free radicals as determined by spin-trapping; (3) an enhanced level of endogenous protein oxidation; (4) a decrease in glutamine synthetase (GS) activity, an enzyme very sensitive to oxidative damage; and (5) demonstration of protection from an IRI by administering the spin- trapping agent alpha-phenyl-tert-butyl nitrone (PBN). The novel observation that PBN offers protection from the lethality brought on by a brain IRI appears to be clearly linked to the ability of the administered spin-trap to inhibit oxidative damage as evidenced by the decreased amount of brain protein oxidation and the prevention of an IRI-mediated loss of GS activity in treated animals. Aged gerbils are more sensitive to the lethal action of a brain IRI than younger animals, but they are protected by PBN administration as are the younger animals. Older gerbils have a significantly higher level of oxidized protein in the brain. Older gerbils have decreased activities of GS and neutral protease, the enzyme that removes oxidized protein, than younger animals. Chronic twice daily administration of PBN (32 mg/kg) for 14 days to older animals significantly lowered brain oxidized protein levels and raised GS and neutral protease activity to those observed in younger animals. Cessation of PBN administration resulted in a time-dependent restoration of protein oxidation levels and enzyme activities back to those observed prior to spin-trap administration. Older gerbils exhibit significantly higher errors in a radial arm maze than younger animals, but older gerbils that had received chronic daily treatments of PBN (32 mg/kg) for 14 days committed significantly less errors than untreated controls. The errors committed in PBN-treated animals was decreased down to the level of those observed in younger animals. Clearly the spin-trapping agent, PBN, appears to have promise in: (1)elucidation of the role of oxidative damage in normal brain function during aging, (2) understanding the development of pathological conditions, and (3) development of treatment regimens for prevention of damage that occurs during the development of pathological conditions and in aging. Institutional address: Department of Pharmacology Chandler Medical Center University of Kentucky Lexington 40536. PS: PBN is patented in Europe as a hair-growth stimulator. Does make it a bit relevant. Peter H. Proctor, PhD, MD (713) 960-1616 David S. Stodolsky, PhD * Social * Internet: Tornskadestien 2, st. th. * Research * Tel.: + 45 38 33 03 30 DK-2400 Copenhagen NV, Denmark * Methods * Fax: + 45 38 33 88 80 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=3944