Abstract |
This study examined whether substitution of chromosome 5 containing the CYP4A genes from Brown Norway rat onto the Dahl S salt-sensitive (SS) genetic background upregulates the renal production of 20-HETE and attenuates the development of hypertension. The expression of CYP4A protein and the production of 20-HETE were significantly higher in the renal cortex and outer medulla of SS.5(BN) (chromosome 5-substituted Brown Norway rat) consomic rats fed either a low- salt (LS) or high- salt (HS) diet than that seen in SS rats. The increase in the renal production of 20-HETE in SS.5(BN) rats was associated with elevated expression of CYP4A2 mRNA. MAP measured by telemetry rose from 117 ± 1 to 183 ± 5 mmHg in SS rats fed a HS diet for 21 days, but only increased to 151 ± 5 mmHg in SS.5(BN) rats. The pressure-natriuretic and diuretic responses were twofold higher in SS.5(BN) rats compared with SS rats. Protein excretion rose to 354 ± 17 mg/day in SS rats fed a HS diet for 21 days compared with 205 ± 13 mg/day in the SS.5(BN) rats, and the degree of glomerular injury was reduced. Baseline glomerular capillary pressure (Pgc) was similar in SS.5(BN) rats (43 ± 1 mmHg) and Dahl S (44 ± 2 mmHg) rats. However, Pgc increased to 59 ± 3 mmHg in SS rats fed a HS diet for 7 days, while it remained unaltered in SS.5(BN) rats (43 ± 2 mmHg). Chronic administration of an inhibitor of the synthesis of 20-HETE ( HET0016, 10 mg·kg(-1)·day(-1) iv) reversed the antihypertensive phenotype seen in the SS.5(BN) rats. These findings indicate that the transfer of chromosome 5 from the BN rat onto the SS genetic background increases the renal expression of CYP4A protein and the production of 20-HETE and that 20-HETE contributes to the antihypertensive and renoprotective effects seen in the SS.5(BN) consomic strain.
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Authors | Jan M Williams, Fan Fan, Sydney Murphy, Carlos Schreck, Jozef Lazar, Howard J Jacob, Richard J Roman |
Journal | American journal of physiology. Regulatory, integrative and comparative physiology
(Am J Physiol Regul Integr Comp Physiol)
Vol. 302
Issue 10
Pg. R1209-18
(May 15 2012)
ISSN: 1522-1490 [Electronic] United States |
PMID | 22442195
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
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Chemical References |
- Hydroxyeicosatetraenoic Acids
- RNA, Messenger
- 20-hydroxy-5,8,11,14-eicosatetraenoic acid
- Cytochrome P-450 CYP4A
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Topics |
- Animals
- Blood Pressure
(physiology)
- Cytochrome P-450 CYP4A
(genetics, metabolism)
- Disease Models, Animal
- Genetic Therapy
(methods)
- Hydroxyeicosatetraenoic Acids
(metabolism)
- Hypertension
(genetics, metabolism, prevention & control)
- Kidney
(blood supply, metabolism)
- Male
- RNA, Messenger
(metabolism)
- Rats
- Rats, Inbred BN
(genetics)
- Rats, Inbred Dahl
(genetics)
- Time Factors
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