Acute Effects of Antihypertensive Drugs on Autoregulation of Cerebral Blood Flow in Spontaneously Hypertensive Rats

2015 ◽  
pp. 206-212 ◽  
Author(s):  
D. I. Barry ◽  
S. Strandgaard
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Spontaneously Hypertensive Rats ◽  
Antihypertensive Drugs ◽  
Acute Effects ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive

scholarly journals Rapamycin Induces an eNOS (Endothelial Nitric Oxide Synthase) Dependent Increase in Brain Collateral Perfusion in Wistar and Spontaneously Hypertensive Rats

Stroke ◽  
2020 ◽  
Vol 51 (9) ◽  
pp. 2834-2843
Author(s):  
Daniel J. Beard ◽  
Zhaojin Li ◽  
Anna M. Schneider ◽  
Yvonne Couch ◽  
Marilyn J. Cipolla ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Nitric Oxide Synthase ◽  
Spontaneously Hypertensive Rats ◽  
Infarct Volume ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Background and Purpose: Rapamycin is a clinically approved mammalian target of rapamycin inhibitor that has been shown to be neuroprotective in animal models of stroke. However, the mechanism of rapamycin-induced neuroprotection is still being explored. Our aims were to determine if rapamycin improved leptomeningeal collateral perfusion, to determine if this is through eNOS (endothelial nitric oxide synthase)-mediated vessel dilation and to determine if rapamycin increases immediate postreperfusion blood flow. Methods: Wistar and spontaneously hypertensive rats (≈14 weeks old, n=22 and n=15, respectively) were subjected to ischemia by middle cerebral artery occlusion (90 and 120 minutes, respectively) with or without treatment with rapamycin at 30-minute poststroke. Changes in middle cerebral artery and collateral perfusion territories were measured by dual-site laser Doppler. Reactivity to rapamycin was studied using isolated and pressurized leptomeningeal anastomoses. Brain injury was measured histologically or with triphenyltetrazolium chloride staining. Results: In Wistar rats, rapamycin increased collateral perfusion (43±17%), increased reperfusion cerebral blood flow (16±8%) and significantly reduced infarct volume (35±6 versus 63±8 mm 3 , P <0.05). Rapamycin dilated leptomeningeal anastomoses by 80±9%, which was abolished by nitric oxide synthase inhibition. In spontaneously hypertensive rats, rapamycin increased collateral perfusion by 32±25%, reperfusion cerebral blood flow by 44±16%, without reducing acute infarct volume 2 hours postreperfusion. Reperfusion cerebral blood flow was a stronger predictor of brain damage than collateral perfusion in both Wistar and spontaneously hypertensive rats. Conclusions: Rapamycin increased collateral perfusion and reperfusion cerebral blood flow in both Wistar and comorbid spontaneously hypertensive rats that appeared to be mediated by enhancing eNOS activation. These findings suggest that rapamycin may be an effective acute therapy for increasing collateral flow and as an adjunct therapy to thrombolysis or thrombectomy to improve reperfusion blood flow.

Autoregulation of Cerebral Blood Flow in Young and Aged Spontaneously Hypertensive Rats (SHR)

Gerontology ◽  
1984 ◽  
Vol 30 (1) ◽  
pp. 30-36 ◽  
Author(s):  
M. Fujishima ◽  
S. Sadoshima ◽  
J. Ogata ◽  
F. Yoshida ◽  
O. Shiokawa ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive
Sign in / Sign up

Export Citation Format

Share Document