ave shown that the enzyme activity of catalase, in the vastus lateralis, is significantly higher in women than men. Sex Sex Difference in mRNA Content differences have also been observed in other antioxidant enzyme, including manganese-superoxide dismutase, suggesting that women are better protected against reactive oxygen species as compared with men. We also demonstrated that mRNA content for UCP2 was higher in women compared to men. UCP’s can affect IC261 biological activity energy metabolism efficiency by uncoupling ATP production from mitochondrial respiration. UCP2 is involved in the regulation of energy metabolism and might play a role in obesity. UCP2 has also been suggested to affect the production of reactive oxygen species , and regulate the / ratio. Although we are the first to show 
a sex specific difference in mRNA content in the vastus lateralis, this may help to explains why young women are protected against ROS. Furthermore, if UCP2 does play a role in obesity the higher expression in women might help to regulate lipid oxidation. ALDH1A1 is an isoform of the aldehyde dehydrogenase superfamily primarily responsible for the oxidation of endogenous and exogenous aliphatic and aromatic aldehydes including acetaldehyde, benzaldehyde, 4-hydroxynonenal, malondialdehyde, and retinaldehyde. Recently ALDH1A1 was also shown to convert 3-deoxyglucosone into 2-keto-3-deoxygluconate. In this study we found that the mRNA content was lower in women compared with men, suggesting that men might be able to metabolize aldehydes more efficiently than women. ALDH1A1 has not been well characterized in humans, let alone skeletal muscle, but in 1975694 the mouse liver and human colon there appears to be no sex differences in activity. Further Sex Difference in mRNA Content studies into the implications of ALDH1A1 mRNA sex differences in skeletal muscle need to be conducted. These results also showed sex specific differences in genes involved in cell transport, protein biosynthesis, cell proliferation, signal transduction pathways, transcription and translation. Of interest, women had a 2.2-fold reduction in the solute carrier family 1, member 4 that is involved in glutamate/neutral amino acid transport which could be important in metabolism. Women had a 1.7-fold increase in mRNA content of angiopoietin 1, a factor involved in increasing vascularization to a specific tissue, in this case, muscle; however, there does not seem to be a significant difference in capillarization of the tibialis anterior or vastus lateralis muscle of women compared to men. Women also had a 1.7- and 1.5-fold reduction 17496168 in Dishevelled associated activator of morphogenesis 2, and spectrin- beta- non-erythrocytic 1 which are involved in actin cytoskeleton organization and biogenesis, and barbed-end actin filament capping, respectively. Both are important in muscle cell shape and function. There was an interesting trend in the expression of signal transduction genes and transcription factor genes. Women had a significant up-regulation of the majority of signal transduction related genes and a significant down-regulation of the majority of transcription factor genes. Despite these trends, there was no evidence that one signal transduction pathway was favored over another as the identified genes spanned multiple pathways including the MAPK pathway, frizzled signaling pathway, G-protein coupled receptor protein signaling pathway, and insulin receptor signaling pathway. It is important to note that gene array an
