Temporal profile of the effects of intracisternal injection of magnesium sulfate solution on vasodilation of spastic cerebral arteries in the canine SAH model.
OBJECTIVE
the temporal profiles of the effects of intracisternal injection of magnesium sulfate (MgSO(4)) on vasodilation and cerebrospinal fluid (CSF) magnesium ion (Mg(2+)) concentration were investigated in the canine subarachnoid hemorrhage (SAH) model.


METHODS
cerebral vasospasm was induced using the two-hemorrhage model in seven female beagles. On day 7, 0.5 ml/kg of 15 mmol/l MgSO(4) in Ringer solution was injected into the cerebellomedullary cistern. Angiography was performed on day 1 (before SAH), and before and 1, 3, and 6 h after the intracisternal injection on day 7. CSF Mg(2+) was measured at the same time.


RESULTS
the diameters of the basilar artery (BA), vertebral artery (VA), and superior cerebellar artery (SCA) before the intracisternal injection on day 7 were 0.59 ± 0.15, 0.41 ± 0.17, and 0.35 ± 0.17 mm, respectively, and were significantly decreased (p < 0.01) compared with the baseline diameters on day 1. The BA diameters at 1 h (0.74 ± 0.16 mm) and 3 h (0.73 ± 0.13 mm), the VA diameter at 1 h (0.64 ± 0.14 mm), and the SCA diameter at 3 h (0.54 ± 0.08 mm) after the injection were significantly increased (p < 0.05). The CSF Mg(2+) concentration was significantly increased (p < 0.01) at 1 h (3.59 ± 0.76 mEq/l) and 3 h (2.00 ± 0.31 mEq/l) after the injection compared with the baseline value (1.35 ± 0.23 mEq/l).


CONCLUSIONS
the reversible effect of intracisternal MgSO(4) solution injection on the spastic artery depends on maintenance of the optimal CSF Mg(2+) concentration.
Department of Neurosurgery, Juntendo University Shizuoka Hospital, 1129 Nagaoka, Izunokuni, Shizuoka 410-2295, Japan. kmori@med-juntendo.jp
Kentaro
K
Mori
Masahiro
M
Miyazaki
Yasukazu
Y
Hara
Yasuhisa
Y
Aiko
Takuji
T
Yamamoto
Yasuaki
Y
Nakao
Takanori
T
Esaki
D000792:Angiography / Q000379:methods; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology / Q000627:therapeutic use*; D002536:Cerebral Arteries / Q000473:pathology*; D002946:Cisterna Magna / Q000187:drug effects; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D008274:Magnesium / Q000134:cerebrospinal fluid; D008278:Magnesium Sulfate / Q000494:pharmacology / Q000627:therapeutic use*; D008279:Magnetic Resonance Imaging / Q000379:methods; D013345:Subarachnoid Hemorrhage / Q000134:cerebrospinal fluid / Q000150:complications / Q000473:pathology; D013997:Time Factors; D014664:Vasodilation / Q000187:drug effects*; D020301:Vasospasm, Intracranial / Q000134:cerebrospinal fluid / Q000188:drug therapy* / Q000209:etiology
D002121:Calcium Channel Blockers; D008278:Magnesium Sulfate; D008274:Magnesium