Novel vasodilatory effect of intracisternal injection of magnesium sulfate solution on spastic cerebral arteries in the canine two-hemorrhage model of subarachnoid hemorrhage.
OBJECTIVE
The extracellular Mg++ has a vasodilatory effect on the cerebral artery. The present study investigated the effect of intracisternal injection of MgSO4 solution on cerebral vasospasm in a canine model of subarachnoid hemorrhage (SAH).


METHODS
Subarachnoid hemorrhage was induced in 10 beagles using the two-hemorrhage model. Angiography of the vertebrobasilar artery was performed on Day 1 (baseline values before SAH) and on Day 7 (during cerebral vasospasm after induced SAH) before and after intracisternal injection of 0.5 ml/kg of 15 mmol/L MgSO4 solution into the cerebellomedullary cistern.


RESULTS
The cerebrospinal fluid Mg++ concentration was significantly increased to 3.15 +/- 1.14 mEq/L after intracisternal injection from the preinjection value (1.45 +/- 0.09 mEq/L; p < 0.01). The diameters of the basilar artery, vertebral artery, and superior cerebellar artery on Day 7 were significantly decreased to 58.0 +/- 10.9%, 71.0 +/- 10.1%, and 60.9 +/- 13.8%, respectively, of their baseline diameters on Day 1 (p < 0.01). After intracisternal injection of MgSO4, these diameters significantly increased to 73.8 +/- 14.3%, 83.0 +/- 14.8%, and 74.1 +/- 13.5%, respectively (p < 0.01).


CONCLUSIONS
Intracisternal injection of MgSO4 solution causes significant dilation of spastic cerebral arteries in the canine two-hemorrhage model of SAH.
Department of Neurosurgery, Shizuoka Hospital, Shizuoka, Japan.
Kentaro
K
Mori
Masahiro
M
Miyazaki
Yasukazu
Y
Hara
Yasuhisa
Y
Aiko
Takuji
T
Yamamoto
Yasuaki
Y
Nakao
D000818:Animals; D002533:Cerebral Angiography; D002536:Cerebral Arteries / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology*; D002946:Cisterna Magna; D004285:Dogs; D007267:Injections; D008278:Magnesium Sulfate / Q000008:administration & dosage* / Q000134:cerebrospinal fluid / Q000494:pharmacology*; D012996:Solutions; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000503:physiopathology*; D014665:Vasodilator Agents; D020301:Vasospasm, Intracranial / Q000188:drug therapy* / Q000503:physiopathology*
D012996:Solutions; D014665:Vasodilator Agents; D008278:Magnesium Sulfate