Angiogenesis detected after embolic stroke in rat brain using magnetic resonance T2*WI.
OBJECTIVE
This study uses T(2)* weighted imaging (T2*WI) to measure the temporal evolution of cerebral angiogenesis in rats subjected to embolic stroke up to 6 weeks after stroke onset with or without sildenafil treatment. Method- Male Wistar rats were subjected to embolic stroke and treated with saline (n=10) or with sildenafil (n=11), with treatment initiated at 24 hours and continued daily for 7 days after onset of ischemia. T2*WI measurements were performed at 24 hours after embolization and weekly up to 6 weeks using a 7-Tesla system. Histological measurements were obtained at 6 weeks after MRI scans.


RESULTS
Using T2*WI, cerebral angiogenesis was detected starting from 4 weeks and from 2 weeks after onset of embolic stroke in saline and sildenafil treated rats, respectively. Significant differences in the temporal and spatial features of angiogenesis after embolic stroke up to 6 weeks after onset of stroke were found between saline and sildenafil treated rats and were identified with T2*WI. MRI permeability parameter, K(i), complementarily detected angiogenesis after ischemia in embolic stroke rats. Sildenafil treatment of stroke rats significantly enhanced the angiogenesis, as confirmed histologically.


CONCLUSIONS
T2*WI can quantitatively measure the temporal evolution of angiogenesis in rats subjected to embolic stroke. Compared to control rats, sildenafil treatment significantly increased angiogenesis in treated animals up to 6 weeks after stroke.
Ding
Guangliang
G
Henry Ford Hospital, Neurology Department, Detroit, MI 48202, USA.
Jiang
Quan
Q
Li
Lian
L
Zhang
Li
L
Zhang
Zheng Gang
ZG
Ledbetter
Karyn A
KA
Gollapalli
Lakshman
L
Panda
Swayamprava
S
Li
Qingjiang
Q
Ewing
James R
JR
Chopp
Michael
M
D000818:Animals; D001921:Brain / Q000098:blood supply / Q000187:drug effects; D001931:Brain Mapping / Q000379:methods; D002536:Cerebral Arteries / Q000033:anatomy & histology / Q000187:drug effects*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D004195:Disease Models, Animal; D020766:Intracranial Embolism / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008833:Microcirculation / Q000033:anatomy & histology / Q000187:drug effects; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D010879:Piperazines / Q000494:pharmacology* / Q000627:therapeutic use; D011237:Predictive Value of Tests; D011687:Purines / Q000494:pharmacology / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function / Q000187:drug effects; D000068677:Sildenafil Citrate; D020521:Stroke / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D013450:Sulfones / Q000494:pharmacology* / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000494:pharmacology / Q000627:therapeutic use
D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate