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Age‐dependent intrarenal expression of nitric oxide (NO) synthase isoforms in sheep
Author(s) -
Smith Francine Gabriel,
Hart David,
Qi Wei,
Reno Carol
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1216-c
Subject(s) - medicine , endocrinology , nitric oxide synthase , enos , renal cortex , kidney , gene isoform , cortex (anatomy) , renal medulla , messenger rna , medulla , medullary cavity , biology , endothelial nos , nitric oxide , biochemistry , gene , neuroscience
Previously we showed that NO plays an age‐dependent role in modulating renal haemodynamics and function during postnatal maturation in conscious lambs (Sener & Smith, 2001; 2001). The production of NO is mediated by three different isoforms of NO synthase (NOS): nNOS ‐ NOS I; iNOS ‐ NOS II; eNOS ‐ NOS III. In the present study, we assessed mRNA expression of NOS I ‐ III during ontogeny in the ovine kidney. Kidney tissue was obtained from sheep aged 24 h, 1, 3, 6, and 12 weeks (N=3 at each age). Corresponding cortical and medullary samples were obtained from the same location in each kidney and frozen in liquid N 2 Following isolation of RNA, mRNA levels for NOS I – III were assessed using RT‐PCR and validated sheep‐specific primers; data were normalized to β‐actin. There was an overall effect of age on NOS expression for all three isoforms (p<0.001, ANOVA and Holm‐Sidak). NOS I mRNA expression was higher in cortex than medulla at all postnatal ages. Medullary levels decreased during the first week, and cortical levels decreased from 3 – 12 weeks. NOS II mRNA levels in the cortex were higher than in the medulla until 3 weeks, when cortical values decreased; medullary values then fluctuated in a defined pattern over 3 – 12 weeks. In contrast, medullary NOS III mRNA levels were higher than cortical values at 24 h, and again from 3 – 12 weeks; cortical values increased and medullary values decreased after 1 week. These data indicate that in the ovine kidney, NOS I – III isoforms display an age‐dependent pattern of expression, which may provide insight into the age‐dependent role of NO in modulating renal haemodynamics and function during ontogeny.