[Changes in endothelial cellular adhesion molecule mRNA expressions in the cerebral blood vessels of rats with prestroke condition caused by simulated cold wave].
OBJECTIVE
To study the changes in the mRNA expression of endothelial cellular adhesion molecules in the cerebral blood vessels in rats with prestroke condition caused by simulated cold wave.


METHODS
Two-kidney two-clip renovascular hypertension was induced in 48 male SD rats, which were subsequently randomly assigned into cold wave exposure and non-exposed group (n=24). Each group was further divided into 4 sub-groups according to their systolic blood pressure, namely the sham-operated group with blood pressure (BP)<140 mmHg, mild hypertensive group with BP of 160-199 mmHg, moderate hypertensive group with BP of 200-219 mmHg, and severe hypertensive group with BP no less than 220 mmHg. Cold wave exposure was simulated by housing the rats in an artificial climate chamber with 3 cycles of 12 h light at 22 degrees celsius; and 12 h dark at 4 degrees celsius;. The non-exposed group was kept at 22 degrees celsius; throughout the experiment. After the exposure, the rats were sacrificed and the tissues of the frontal lobe were slice into 2.0-mm-thick coronal sections for real-time RT-PCR detection of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and p-selectin mRNA expressions. The 5.0-microm-thick frozen sections from the bregma section underwent in situ hybridization of VCAM-1, ICAM-1, and p-selectin. The other sections were stained with HE to observe the infarct lesions, and the rats with cerebral infraction were excluded from the statistical analysis.


RESULTS
In rats with cold wave exposure-induced prestroke condition and BP <220 mmHg, VCAM-1, ICAM-1, and p-selectin mRNA expressions all increased compared with those in the non-exposed group. In rats with BP>or=220 mmHg and cold exposure, the expressions all decreased to some extent compared with those in the non-exposed treatment. In the non-exposed rats, a positive correlation of BP to VCAM-1, ICAM-1, and p-selectin mRNA expressions were noted, and this correlation was also found in cold-wave-exposed rats with BP <220 mmHg; VCAM-1, ICAM-1, and p-selectin mRNA expressions decreased dramatically in the exposed rats with BP >or=220 mmHg compared with those in rats with BP <220 mmHg.


CONCLUSIONS
Persistent and severe hypertension impairs the modulatory function of the cerebral vascular endothelia, which is a prerequisite for the stroke vulnerability. The modulatory function deteriorates as the BP further increases.
Lin
Jian-Wen
JW
Department of Neurology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China. l_jianwen@163.com
Shi
Xiao-Geng
XG
Xie
Long-Chang
LC
Liu
Chun-Ling
CL
Huang
Ru-Xun
RX
D000818:Animals; D001273:Atmosphere Exposure Chambers; D002536:Cerebral Arteries / Q000378:metabolism; D003080:Cold Temperature; D004780:Environment, Controlled; D004867:Equipment Design; D006978:Hypertension, Renovascular / Q000150:complications / Q000378:metabolism*; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D008297:Male; D019007:P-Selectin / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D020521:Stroke / Q000209:etiology / Q000378:metabolism*; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*
D019007:P-Selectin; D012333:RNA, Messenger; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1