Gz. Wei et al., INCREASED PLASMA ENDOTHELIN-1 CONCENTRATION IN PATIENTS WITH ACUTE CEREBRAL INFARCTION AND ACTIONS OF ENDOTHELIN-1 ON PIAL ARTERIOLES OF RAT, Chinese medical journal, 106(12), 1993, pp. 917-921
In acute cerebral ischemia there are severe damages of endothelium whi
ch have been recognized as the stimuli to secrete endothelin-1, an end
othelium--derived peptide and the most potent vasoconstrictor ever kno
wn. This study was to measure plasma endothelin-1 level in patients wi
th cerebral infarction and explore the relationship between endothelin
-1 and ischemic stroke. The possible involvement of endothelin-1 in lo
cal regulation of cerebral arterioles was also investigated. Plasma le
vels of endothelin-1 were measured by radioimmunoassay in 21 patients.
Using a micro video system, the endothelin-1 actions were also observ
ed on rat pial arterioles in vivo, and with incomplete cerebral ischem
ia model (rat), effect of ischemia affects the endothelin-1 action. Th
ere was a marked increase in plasma endothelin-1 level in the patients
and the elevation persisted during the acute and subacute period of s
troke. There was a positive correlation between the peptide concentrat
ion and infarct size (r = 0.655, P<0.01). In rats, endothelin-1 (dose
range: 10(-10) mole / L -10(-7) mole / L) induced a dose-dependent art
eriole contraction after subdural administration. Arteriole calibers w
ere decreased by 27.7% +/- 3.8% (10(-9) mole / L), 46.8% +/- 4.9% (10(
-8) mole / L) and 78.5% +/- 4.7% (10(-7) mole / L), respectively. Cere
bral ischemia significantly enhanced the action of endothelin-1 (96.4%
7.2% vs 58.2% +/- 6.8%). Endothelin-1 plays an important role in regu
lating local circulation of ischemic brain. The notable and lasting in
crease in plasma level of endothelin-1 are associated with cerebral is
chemia and infarction. The peptide seems to be involved in the pathoph
ysiology of acute cerebral ischemia and plays a deleterious role in th
e progress of cerebral infarction.