scholarly journals Involvement of Epithelial Na+ Channel in the Elevated Myogenic Response in Posterior Cerebral Arteries from Spontaneously Hypertensive Rats

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Soo-Kyoung Choi ◽  
Soo-In Yeon ◽  
Youngin Kwon ◽  
Seonhee Byeon ◽  
Young-Ho Lee
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Cerebral Arteries ◽  
Na Channel ◽  
Myogenic Response ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Epithelial Na Channel

Prevention of stroke and preservation of the functions of cerebral arteries by treatment with perindopril in stroke-prone spontaneously hypertensive rats

1998 ◽  
Vol 76 (1) ◽  
pp. 26-34 ◽  
Author(s):  
H Wang ◽  
J S Smeda ◽  
RMKW Lee
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Cerebral Arteries ◽  
Subsequent Development ◽  
Treatment Withdrawal ◽  
Prolonged Treatment ◽  
Control Group ◽  
Myogenic Response ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Middle Cerebral Arteries

The aim of this study was to determine whether the prevention of stroke with perindopril treatment in stroke-prone spontaneously hypertensive rats (SHRSP) is associated with the preservation of the myogenic properties of the cerebral arteries. After weaning at 4 weeks of age, male SHRSP were fed a Japanese-style rat diet with high salt to induce stroke development. Treatment with perindopril was given by gavage every morning beginning at 6 weeks of age. There were three experimental groups: two groups treated with 4 mg ·kg-1 ·day-1 perindopril for different durations (8 or 12 weeks) and one control group consisting of littermates given distilled water. All the control animals developed stroke and died within 14 weeks of age, and myogenic response of the middle cerebral arteries (MCA) to pressure increase was lost in these animals. In contrast, all the treated SHRSP survived during the treatment period, and myogenic response of the MCA was preserved. After withdrawal of the treatment, SHRSP treated for a longer period (12 weeks) also survived longer than those treated for a shorter period (8 weeks). The subsequent development of stroke and death following treatment withdrawal after 8 or 12 weeks of treatment was associated with the loss of pressure-dependent constriction in MCA. A longer treatment duration also increased the stiffness of the MCA. MCA from SHRSP after 12 weeks of treatment had smaller external and lumen diameters, and thicker walls than those from the 8-week treatment group. In a separate study, we found that treatment of SHRSP with 1 or 4 mg ·kg-1 ·day-1 of perindopril for 24 weeks beginning at 6 weeks of age also protected them against death related to stroke, because these rats survived up to 43 weeks of age, when the experiment was terminated. We conclude that there is an association between the absence of myogenic response in cerebral arteries and stroke development in SHRSP. Perindopril treatment preserves the myogenic response of MCA in SHRSP and prevents the stroke development in these animals. A prolonged treatment could increase the survival of SHRSP through a remodelling of the MCA and increasing the stiffness of the cerebral arteries.Key words: autoregulation, myogenic response, cerebral artery, stroke, perindopril, hypertension.

Alterations of the Nitric Oxide Pathway in Cerebral Arteries from Spontaneously Hypertensive Rats

2002 ◽  
Vol 39 (3) ◽  
pp. 378-388 ◽  
Author(s):  
Ana M. Briones ◽  
María J. Alonso ◽  
Raquel Hernanz ◽  
Marta Miguel ◽  
Mercedes Salaices
Keyword(s):  
Nitric Oxide ◽  
Spontaneously Hypertensive Rats ◽  
Cerebral Arteries ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Nitric Oxide Pathway

scholarly journals Enhanced myogenic response in the afferent arteriole of spontaneously hypertensive rats

2010 ◽  
Vol 298 (6) ◽  
pp. H1769-H1775 ◽  
Author(s):  
YiLin Ren ◽  
Martin A. D'Ambrosio ◽  
Ruisheng Liu ◽  
Patrick J. Pagano ◽  
Jeffrey L. Garvin ◽  
...  
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Perfusion Pressure ◽  
Intraluminal Pressure ◽  
Myogenic Response ◽  
Afferent Arteriole ◽  
Hypertensive Rats ◽  
Luminal Diameter ◽  
Spontaneously Hypertensive ◽  
Before And After ◽  
Wistar Kyoto

Spontaneously hypertensive rats (SHRs) have normal glomerular capillary pressure even though renal perfusion pressure is higher, suggesting that preglomerular vessels exhibit abnormally high resistance. This may be due to increased superoxide (O2−) production, which contributes to the vasoconstriction in hypertension. We tested the hypothesis that the myogenic response of the afferent arteriole (Af-Art) is exaggerated in SHRs because of increased levels of reactive oxygen species (ROS). Single Af-Arts were microdissected from kidneys of SHRs and Wistar-Kyoto (WKY) rats and microperfused in vitro. When perfusion pressure in the Af-Art was increased stepwise from 60 to 140 mmHg, the luminal diameter decreased by 8.4 ± 2.9% in WKY Af-Arts but fell by 29.3 ± 5.6% in SHR Af-Arts. To test whether ROS production is enhanced during myogenic response in SHRs, we measured chloromethyl-dichlorodihydrofluorescein diacetate acetyl ester (CM-H2DCFDA) florescence before and after increasing intraluminal pressure from 60 to 140 mmHg. Pressure-induced increases in ROS were fourfold greater in SHR Af-Arts compared with WKY Af-Arts (SHR, 48.0 ± 2.2%; and WKY, 12.2 ± 0.3%). To test whether O2− contributes to the myogenic response in SHRs, either the membrane-permeant O2− scavenger Tempol or the nox2-based NADPH oxidase (NOX2) inhibitor gp91 ds-tat were added to the Af-Art lumen and bath and the myogenic response was tested before and after treatment. Both Tempol (10−4 M) and gp91 ds-tat (10−5 M) significantly attenuated the pressure-induced constriction in SHR Af-Arts but not in WKY Af-Arts. We conclude that 1) pressure-induced constriction is exaggerated in SHR Af-Arts, 2) NOX2-derived O2− may contribute to the enhanced myogenic response, and 3) O2− exerts little influence on the myogenic response under normotensive conditions.

Effects of losartan on cerebral arteries in stroke-prone spontaneously hypertensive rats

1996 ◽  
Vol 14 (11) ◽  
pp. 1341-1348 ◽  
Author(s):  
Elisabeth Vacher ◽  
Christine Richer ◽  
Jean-Fran??ois Giudicelli
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Cerebral Arteries ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive
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