Attenuation and recovery of brain stem autoregulation in spontaneously hypertensive rats

Kazunori Toyoda, Kenichiro Fujii, Setsuro Ibayashi, Takanari Kitazono, Tetsuhiko Nagao, Hitonori Takaba, Masatoshi Fujishima

研究成果: ジャーナルへの寄稿記事

16 引用 (Scopus)

抄録

Cerebral large arteries dilate actively around the lower limits of CBF autoregulation, mediated at least partly by nitric oxide, and maintain CBF during severe hypotension. We tested the hypothesis that this autoregulatory response of large arteries, as well as the response of arterioles, is altered in spontaneously hypertensive rats (SHR) and that the altered response reverts to normal during long-term antihypertensive treatment with cilazapril, an angiotensin-converting enzyme inhibitor. In anesthetized 6- to 7-month-old normotensive Wistar-Kyoto rats (WKY), 4- and 6- to 7-month-old SHR without antihypertensive treatment, and 6- to 7-month-old SHR treated with cilazapril for 10 weeks, local CBF to the brain stem was determined with laser-Doppler flowmetry and diameters of the basilar artery and its branches were measured through a cranial window during stepwise hemorrhagic hypotension. The lower limit of CBF autoregulation shifted upward in untreated SHR to 90 to 105 mm Hg from 30 to 45 mm Hg in WKY, and it reverted to 30 to 45 mm Hg in treated SHR. In response to severe hypotension, the basilar artery dilated by 21 ± 6% (mean ± SD) of the baseline internal diameter in WKY. The vasodilation was impaired in untreated SHR (10 ± 8% in 4-mo-old SHR and 4 ± 5% in 6- to 7-month-old SHR), and was restored to 22 ± 10% by treatment with cilazapril (P < 0.005). Dilator responses of branch arterioles to hypotension showed similar attenuation and recovery as that of the basilar artery. The data indicate that chronic hypertension impairs the autoregulatory dilation of the basilar artery as well as branch arterioles and that antihypertensive treatment with cilazapril restores the diminished dilation toward normal.

元の言語英語
ページ(範囲)305-310
ページ数6
ジャーナルJournal of Cerebral Blood Flow and Metabolism
18
発行部数3
DOI
出版物ステータス出版済み - 3 1998

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Inbred SHR Rats
Brain Stem
Homeostasis
Cilazapril
Basilar Artery
Hypotension
Inbred WKY Rats
Arterioles
Antihypertensive Agents
Dilatation
Laser-Doppler Flowmetry
Cerebral Arteries
Angiotensin-Converting Enzyme Inhibitors
Vasodilation
Nitric Oxide
Arteries
Hypertension

All Science Journal Classification (ASJC) codes

  • Neurology
  • Clinical Neurology
  • Cardiology and Cardiovascular Medicine

これを引用

Attenuation and recovery of brain stem autoregulation in spontaneously hypertensive rats. / Toyoda, Kazunori; Fujii, Kenichiro; Ibayashi, Setsuro; Kitazono, Takanari; Nagao, Tetsuhiko; Takaba, Hitonori; Fujishima, Masatoshi.

:: Journal of Cerebral Blood Flow and Metabolism, 巻 18, 番号 3, 03.1998, p. 305-310.

研究成果: ジャーナルへの寄稿記事

Toyoda, Kazunori ; Fujii, Kenichiro ; Ibayashi, Setsuro ; Kitazono, Takanari ; Nagao, Tetsuhiko ; Takaba, Hitonori ; Fujishima, Masatoshi. / Attenuation and recovery of brain stem autoregulation in spontaneously hypertensive rats. :: Journal of Cerebral Blood Flow and Metabolism. 1998 ; 巻 18, 番号 3. pp. 305-310.
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abstract = "Cerebral large arteries dilate actively around the lower limits of CBF autoregulation, mediated at least partly by nitric oxide, and maintain CBF during severe hypotension. We tested the hypothesis that this autoregulatory response of large arteries, as well as the response of arterioles, is altered in spontaneously hypertensive rats (SHR) and that the altered response reverts to normal during long-term antihypertensive treatment with cilazapril, an angiotensin-converting enzyme inhibitor. In anesthetized 6- to 7-month-old normotensive Wistar-Kyoto rats (WKY), 4- and 6- to 7-month-old SHR without antihypertensive treatment, and 6- to 7-month-old SHR treated with cilazapril for 10 weeks, local CBF to the brain stem was determined with laser-Doppler flowmetry and diameters of the basilar artery and its branches were measured through a cranial window during stepwise hemorrhagic hypotension. The lower limit of CBF autoregulation shifted upward in untreated SHR to 90 to 105 mm Hg from 30 to 45 mm Hg in WKY, and it reverted to 30 to 45 mm Hg in treated SHR. In response to severe hypotension, the basilar artery dilated by 21 ± 6{\%} (mean ± SD) of the baseline internal diameter in WKY. The vasodilation was impaired in untreated SHR (10 ± 8{\%} in 4-mo-old SHR and 4 ± 5{\%} in 6- to 7-month-old SHR), and was restored to 22 ± 10{\%} by treatment with cilazapril (P < 0.005). Dilator responses of branch arterioles to hypotension showed similar attenuation and recovery as that of the basilar artery. The data indicate that chronic hypertension impairs the autoregulatory dilation of the basilar artery as well as branch arterioles and that antihypertensive treatment with cilazapril restores the diminished dilation toward normal.",
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AU - Toyoda, Kazunori

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AU - Takaba, Hitonori

AU - Fujishima, Masatoshi

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