Effect of free radical scavenger (tempol) on intrarenal oxygenation in hypertensive rats as evaluated by BOLD MRI

Authors

  • Lu-Ping Li PhD,

    Corresponding author
    1. Department of Radiology, Evanston Northwestern Healthcare, Evanston, Illinois, and Northwestern University Medical School, Chicago, Illinois
    • Radiology Department/Center for Advanced Imaging, Walgreen Building, Suite G507, Evanston Hospital, 2650 Ridge Avenue, Evanston, IL 60201
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  • Belinda S. Y. Li PhD,

    1. GE Healthcare, Evanston, Illinois
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  • Pippa Storey PhD,

    1. Department of Radiology, Evanston Northwestern Healthcare, Evanston, Illinois, and Northwestern University Medical School, Chicago, Illinois
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  • Laura Fogelson,

    1. Department of Radiology, Evanston Northwestern Healthcare, Evanston, Illinois, and Northwestern University Medical School, Chicago, Illinois
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  • Wei Li MD,

    1. Department of Radiology, Evanston Northwestern Healthcare, Evanston, Illinois, and Northwestern University Medical School, Chicago, Illinois
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  • Pottumarthi Prasad PhD

    1. Department of Radiology, Evanston Northwestern Healthcare, Evanston, Illinois, and Northwestern University Medical School, Chicago, Illinois
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Abstract

Purpose

To demonstrate a differential response following administration of a free radical scavenger, tempol, in kidneys of hypertensive compared to normotensive rats.

Material and Methods

Data were obtained in spontaneously hypertensive rats (SHR, N = 5). Wistar-Kyoto rats (WKY, N = 6) were used as normotensive controls.

Results

Consistent with prior reports, SHRs show a significant response to tempol (R2*decreased from 40.56 ± 0.66 second−1 to 28.58 ± 0.6 second–1 in medulla, P < 0.05), while WKY rats exhibit a minimal change (R2* measuring 22.36 ± 4.38 second–1 pre-tempol and 21.57 ± 4.78 second–1 post-tempol, in medulla). The post-tempol R2* in SHR was found to be comparable to pre-tempol values in WKY rats, suggesting an improved medullary oxygenation in SHRs.

Conclusion

Based on both baseline R2* values and the differential effect of the free radical scavenger on renal medullary oxygenation, BOLD MRI can distinguish hypertensive from normal kidney in rats. J. Magn. Reson. Imaging 2005;21:245–248. © 2005 Wiley-Liss, Inc.

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