Effect of melatonin on cerebral vasospasm following experimental subarachnoid hemorrhage.
OBJECTIVE
The current study was undertaken to determine whether melatonin therapy reverses vasospasm and prevents apoptosis by inhibiting lipid peroxidation in an experimental subarachnoid hemorrhage (SAH) model.


METHODS
The rabbits were divided into four groups as follows: Group 1, SAH + melatonin (5 mg/kg/i.p. BID) simultaneously with SAH (n = 6); Group 2, SAH + melatonin (5 mg/kg/i.p. BID) treated 2 hours after SAH (n = 6); Group 3, control group (n = 4); Group 4, SAH only (n = 6). Light microscopic examinations of the basilar arteries were performed to demonstrate the pathophysiological changes of the arterial wall with hematoxylin- eosin. Apoptosis: Immunohistology using the ApopTag Peroxidase In Situ Apoptosis Detection Kit was used to demonstrate apoptosis in a cross section of basilary arteries. Apoptotic index was calculated as the number of the immunoreactive nuclei per total number of endothelial cells, and expressed as a percentage.


RESULTS
The results of measurements of diameters of the vessels between groups were significantly different (p = 0.028). While basilar arteries of the SAH only group showed 57% constriction, Groups 1 and 2 were calculated as 33 and 26% constriction, respectively, compared with the control group (p < 0.05). And also Groups 1 and 2 showed significant protection of apoptosis compared with Group 4. The difference between the four groups was tested by Kruskal-Wallis test and the significance between the two groups was tested by Mann- Whitney U-test.


CONCLUSIONS
Melatonin with its strong antioxidant effect can prevent SAH-induced vasospasm and apoptosis of endothelial cells of vessels.
Aydin
M Volkan
MV
Department of Neurosurgery, Baskent University, 1250, Yuregir-Adana/Turkey. volkan8@hotmail.com
Caner
Hakan
H
Sen
Orhan
O
Ozen
Ozlem
O
Atalay
Basar
B
Cekinmez
Melih
M
Altinors
Nur
N
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001488:Basilar Artery / Q000187:drug effects / Q000473:pathology; D002452:Cell Count / Q000379:methods; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000473:pathology; D005260:Female; D008297:Male; D008550:Melatonin / Q000627:therapeutic use*; D011817:Rabbits; D013345:Subarachnoid Hemorrhage / Q000150:complications* / Q000473:pathology; D020301:Vasospasm, Intracranial / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology
D008550:Melatonin