K024: Increased ornithine decarboxylase expression in kidneys of dahl salt sensitive rats

• Published in: American journal of hypertension 2000-04, Vol.13 (S2), p.289A-289A
• Main Authors: Hayashi, T., Tsujino, T., Iwata, S., Watari, Y., Nonaka, H., Harada, H., Mohri, T., Watsuji, Y., Yokayama, M.
• Format: Article
• Language: English
• Subjects: dahl rat; Ornithine decarboxylase; renal hypertrophy; salt
• ISSN: 0895-7061; 1941-7225; 1879-1905
• DOI: 10.1016/S0895-7061(00)01055-4

Renal hypertrophy is observed in compensation for the development of hypertension. Omithine decarboxylase (ODC) synthesizes polyamines, which are necessary for cellular proliferation. We examined the expression of ODC in the kidneys of Dahl salt-sensitive (SS) or salt-resistent (SR) rats, spontaneously hypertensive rats (SHR), and Wistar-Kyoto rats (WKY). Design and Methods: Male 4-week-old SS rats and SR rats received normal (0.4% NaCl) (SS-L, SR-L) or high-salt (4% NaCl) (SS-H, SR-H) diets for 4 weeks. After 4 weeks, rats were sacrificed and kidneys were isolated 12-week-old SHR and WKY were also sacrificed and kidneys were isolated. The expression of ODC in kidneys was determined by Western blotting. Results: ODC expression in the kidney of SS rats was not significantly different from that of SR rats at 4 weeks of age (SR vs SS: 1.00 ± 0.08 vs 1.09 ± 0.04). But ODC expression in kidneys was increased in the SS-L group than in the SR-L group at 8 weeks of age (SR-L vs SS-L: 1.00 ± 0.96 vs 2.34 ± 0.11, p < 0.01). Moreover, high salt diet increased ODC expression only in SS rats (SS-L vs SS-H: 1.00 ± 0.32 vs 2.13 ± 0.16, p < 0.01) (SR-L vs SR-H: 1.00 ± 0.17 vs 0.97 ± 0.05). ODC expression in kidneys did not differ between SHR and WKY rats (SHR vs WKY: 1.00 ± 0.05 vs 1.10 ± 0.04). Conclusion: Increased ODC expression in kidneys and induction of ODC by high salt diet may cause renal hypertrophy in SS rats.