title: Antioxidant diet, gender and age affect renal expression of nitric oxide synthases in obese diabetic rats.
abstract: Development of diabetic nephropathy (DN) is associated with decreased renal nitric oxide production and increased oxidative stress. We studied nitric oxide synthase (NOS) expression in kidney of obese Zucker fa/fa rats, a model of Type 2 obesity-related DN. Male and female rats received a regular (REG) or antioxidant-fortified (AO) diet starting at age 4 weeks. Quantitative PCR and immunoblot analyses were performed on kidney cortex and medulla to determine levels of endothelial, neuronal and inducible NOS at 6, 13 and 20 weeks of age. Multiple antibody-specific proteins were detected for each form. These may represent monomeric splice forms, post-translationally modified forms and their dimers, consistent with the known complexity of regulation of these enzymes. Levels of eNOS and nNOS are higher in males than females at 6 weeks on the REG diet and 13 weeks on either diet; the relationship is reversed in females at 6 weeks on the AO diet. Levels of eNOS and nNOS are lower on the AO diet compared to REG, in males at 6 and 13 weeks and females at 13 weeks; the reverse is seen in 6 week females and 20 week males. All three isoforms show peak levels in the younger animals, at 6 or 13 weeks. Better preservation of kidney function is associated with higher prevalence of dimers with potential to increase production of NO and lower levels of potentially harmful monomers. Differential expression of NOS isoforms may be linked to renal functional and histopathological changes in this rat model of DN.
authors.affiliation: Department of Biomedical Sciences, Ohio University, Athens, OH 45701, USA. slyvka@ohio.edu
authors.forename: Yuriy
authors.initials: Y
authors.lastname: Slyvka
authors.forename: Zhenchao
authors.initials: Z
authors.lastname: Wang
authors.forename: Jennifer
authors.initials: J
authors.lastname: Yee
authors.forename: Sharon R
authors.initials: SR
authors.lastname: Inman
authors.forename: Felicia V
authors.initials: FV
authors.lastname: Nowak
mesh_terms: D000367:Age Factors; D017398:Alternative Splicing; D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000178:diet therapy* / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D015151:Immunoblotting; D007672:Kidney Cortex / Q000378:metabolism*; D007679:Kidney Medulla / Q000378:metabolism*; D008297:Male; D019001:Nitric Oxide Synthase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011924:Rats, Zucker
chemical_list: D000975:Antioxidants; D020033:Protein Isoforms; D019001:Nitric Oxide Synthase