[Relationship of changes in basement membrane of microvessels after cerebral ischemia/reperfusion and plasminogen activator system in aged rats].
OBJECTIVE
To study the relationship of changes in basement membrane of cerebral micro-vessels and plasminogen activator system after cerebral ischemia/reperfusion (I/R) injury in aged rats.


METHODS
Middle cerebral artery occlusion (MCAO) was produced by the introduction of a thread. Rats were divided randomly into sham-operation group with young rats (cerebral ischemia 3 hours and I/R 6, 12, 24, 72, 144 hours groups), sham-operation group and I/R groups in aged rats (cerebral ischemia 3 hours and I/R 6, 12, 24, 72, 144 hours groups). Immunohistochemical technique, zymogram analysis, and reverse zymogram analysis were used to study changes in basement membrane structure of cerebral-cortex microvessel, type IV collagen (Col IV) and laminin (LN) contents, and plasminogen activator system in every group.


RESULTS
With the increase of age, Col IV and LN contents of the microvessel basement membrane increased. With prolongation of I/R, the contents of Col IV and LN decreased in both young and aged rats, while the contents of tissue plasminogen activator (t-PA), urokinase plasminogen (u-PA) and plasminogen activator inhibitor (PAI-1) expression increased at the beginning and decreased subsequently. Compared with young groups, Col IV (ischemia 3 hours-I/R 12 hours), LN (ischemia 3 hours-I/R 24 hours), t-PA (I/R 6-24 hours) and u-PA (I/R 12-144 hours) expression levels were higher in aged rats, but PAI-1 (I/R 12 and 24 hours) expression was lower. In addition, changes in PAI-1 contents as determined with reverse zymogram analysis method coincided with its immunoexpression.


CONCLUSIONS
With the increase of age, alterations in constituents of cerebro-microvessel basement membrane (Col IV and LN) increased. Injury to cerebro-microvessel basement membrane resulted in more serious changes in aged rats compared with the young rats. Changes in cerebro-microvessel basement membrane after I/R injury in the aged SD rats is related to change in plasminogen activator system.
Liu
Ke
K
Department of Geriatrics, Henan College of Traditional Chinese Medicine, Zhengzhou 450003, Henan, China.
Li
Jian-sheng
JS
Wang
Ming-hang
MH
Liu
Jing-xia
JX
Zhao
Yue-wu
YW
Liu
Zhen-guo
ZG
D000367:Age Factors; D000818:Animals; D001489:Basilar Membrane / Q000378:metabolism / Q000473:pathology*; D002545:Brain Ischemia / Q000378:metabolism / Q000473:pathology*; D004195:Disease Models, Animal; D008297:Male; D055806:Microvessels / Q000378:metabolism / Q000473:pathology*; D010960:Plasminogen Activators / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D015424:Reperfusion
D010960:Plasminogen Activators