Phenyl N-tert-butyl nitrone (PBN) is a spin trap and a free radical scavenger. PBN has been shown to have a variety of pharmacological effects, such as preventing death after endotoxin-induced shock in rodents and increasing the average life span of senescence-accelerated mice. PBN's radical-trapping capabilities are suggested to be responsible for these effects; however, no hard evidence has been obtained for this assumption. In our preliminary studies, using a new method of nitric oxide (NO) detection, PBN was found to inhibit induction of NO synthase (NOS) in vivo in a mouse endotoxin shock model, as well as in activated macrophages in vitro, suggesting that PBN's protective activity could be explained by suppression of overproduction of NO through inhibition of NOS induction. Preliminary data indicate that some PBN-type nitrone spin traps are more effective than PBN itself in the inhibition of NOS induction. Therefore, many PBN-type spin traps will be tested to elucidate structural dependence of the inhibition capacity. Compelling evidence indicates that NOS expression is modulated by oxidant-sensitive transcription factor, nuclear factor kB (NFkB). Therefore, the hypothesis that radical scavenging by PBN-type spin traps decreases the intracellular concentrations of free radicals, thereby preventing NFkB activation and subsequent induction of iNOS, will be tested experimentally.
The specific aims of this project are (A) to determine the structural factors of PBN-type spin traps required for effective inhibition of iNOS induction, (B) to determine the correlation between radical-trapping efficiency of PBN spin traps and the expression of an oxidant-responsive transcription factor, NFkB. The long-term goal of these studies is development of improved drugs for treatment of septic shock and other diseases caused by NO overproduction in human patients.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
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Special Emphasis Panel (ZRG4-ALTX-1 (01))
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Oklahoma Medical Research Foundation
Oklahoma City
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Kotake, Yashige; Moore, Danny R; Vasquez-Walden, Angelica et al. (2003) Antioxidant amplifies antibiotic protection in the cecal ligation and puncture model of microbial sepsis through interleukin-10 production. Shock 19:252-6
Kotake, Yashige; Sang, Hong; Tabatabaie, Tahereh et al. (2002) Interleukin-10 overexpression mediates phenyl-N-tert-butyl nitrone protection from endotoxemia. Shock 17:210-6
Hensley, K; Kotake, Y; Sang, H et al. (2000) Dietary choline restriction causes complex I dysfunction and increased H(2)O(2) generation in liver mitochondria. Carcinogenesis 21:983-9
Reinke, L A; Moore, D R; Sang, H et al. (2000) Aromatic hydroxylation in PBN spin trapping by hydroxyl radicals and cytochrome P-450. Free Radic Biol Med 28:345-50
Stewart, C A; Hyam, K; Wallis, G et al. (1999) Phenyl-N-tert-butylnitrone demonstrates broad-spectrum inhibition of apoptosis-associated gene expression in endotoxin-treated rats. Arch Biochem Biophys 365:71-4
Kotake, Y (1999) Pharmacologic properties of phenyl N-tert-butylnitrone. Antioxid Redox Signal 1:481-99
Kotake, Y; Moore, D R; Sang, H et al. (1999) Continuous monitoring of in vivo nitric oxide formation using EPR analysis in biliary flow. Nitric Oxide 3:114-22
Sang, H; Wallis, G L; Stewart, C A et al. (1999) Expression of cytokines and activation of transcription factors in lipopolysaccharide-administered rats and their inhibition by phenyl N-tert-butylnitrone (PBN). Arch Biochem Biophys 363:341-8
Kotake, Y; Sang, H; Miyajima, T et al. (1998) Inhibition of NF-kappaB, iNOS mRNA, COX2 mRNA, and COX catalytic activity by phenyl-N-tert-butylnitrone (PBN). Biochim Biophys Acta 1448:77-84
Nakae, D; Kotake, Y; Kishida, H et al. (1998) Inhibition by phenyl N-tert-butyl nitrone of early phase carcinogenesis in the livers of rats fed a choline-deficient, L-amino acid-defined diet. Cancer Res 58:4548-51