Hypertension impairs leptomeningeal collateral growth after common carotid artery occlusion: restoration by antihypertensive treatment.
Chronic mild hypoperfusion has been shown to enlarge pial collateral vessels in normal mouse brains. The purpose of this study was to clarify the effect of hypertension on pial collateral vessel development after chronic hypoperfusion using spontaneously hypertensive rats (SHR). In normotensive rats, unilateral common carotid artery (CCA) occlusion enlarged leptomeningeal collateral vessels. CCA occlusion also preserved residual cerebral blood flow (CBF) and attenuated infarct size after middle cerebral artery (MCA) occlusion 14 days later. In contrast, in SHR, CCA occlusion neither enlarged the leptomeningeal anastomosis nor showed protective effects after MCA occlusion. However, decreasing blood pressure using an angiotensin II AT1 receptor blocker restored the beneficial effect of CCA occlusion on collateral growth as well as on residual CBF and infarct size after MCA occlusion. Adaptive responses in CBF autoregulation curves observed 14 days after CCA occlusion in normotensive rats were impaired in untreated SHR, but were restored after antihypertensive treatment. In conclusion, SHR have impaired leptomeningeal collateral growth after CCA occlusion, but antihypertensive treatment restores the beneficial effect of CCA occlusion on collateral circulation.
Department of Neurology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Emi
E
Omura-Matsuoka
Yoshiki
Y
Yagita
Tsutomu
T
Sasaki
Yasukazu
Y
Terasaki
Naoki
N
Oyama
Yukio
Y
Sugiyama
Kenichi
K
Todo
Saburo
S
Sakoda
Kazuo
K
Kitagawa
D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D016893:Carotid Stenosis / Q000188:drug therapy* / Q000503:physiopathology; D003097:Collateral Circulation / Q000187:drug effects* / Q000502:physiology; D004195:Disease Models, Animal; D006973:Hypertension / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008576:Meningeal Arteries / Q000187:drug effects* / Q000502:physiology; D018919:Neovascularization, Physiologic / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar
D000959:Antihypertensive Agents