Insights into Dahl salt-sensitive XXXX revealed by temporal patterns of renal medullary gene expression.

@entity35 @entity101 @entity8 @entity74
Dahl salt-sensitive SS and consomic, salt-resistant SS-13(BN)/Mcw @entity35 possess a highly similar genetic background but exhibit substantial differences in blood pressure salt sensitivity. We used cDNA microarrays to examine sequential changes of mRNA expression of approximately 2,000 currently known @entity35 genes in the renal medulla (a tissue critical for long-term blood pressure regulation) in SS and SS-13(BN)/Mcw @entity35 in response to a high-salt diet (16 h, 3 days, or 2 wk). Differentially expressed genes in each between-group comparison were identified based on a threshold determined experimentally using a reference distribution that was constructed by comparing @entity35 within the same group. A difference analysis of 54 microarrays identified 50 genes that exhibited the most distinct temporal patterns of expression between SS and SS-13(BN)/Mcw @entity35 over the entire time course. Thirty of these genes could be linked to the regulation of arterial blood pressure or @entity8 based on their known involvement in functional pathways such as renal tubular transport, metabolism of vasoactive substances, extracellular matrix formation, and apoptosis. Importantly, the majority of the 30 genes exhibited temporal expression patterns that would be expected to lower arterial pressure and reduce @entity8 in SS-13(BN)/Mcw compared with SS @entity35 . The phenotypic impact of the other 20 genes was less clear. These 50 genes are widely distributed on chromosome 13 and several other chromosomes. This suggested that primary @entity74 , although important, are unlikely to be solely responsible for the full manifestation of this type of @entity101 and associated injury phenotypes. In summary, the results of this study identified a number of pathways potentially important for the amelioration of @entity101 and @entity8 in SS-13(BN)/Mcw @entity35 , and these results generated a series of testable hypotheses related to the role of the renal medulla in the complex mechanism of salt-sensitive @entity101 .
