ISSN: 1300-0292
İndekslendiği Dizinler: SCIENCE CITATION INDEX EXPANDED
CINAHL, Index Copernicus,
Chemical Abstracts (CA),
Excerpta Medica / EMBASE
Dil: Türkçe, İngilizce
İçerik: Orijinal Araştırma, Derleme, Editöre Mektup, Olgu Sunumu, Tıp Eğitimi, Tıbbi Kitap İncelemeleri
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ORIGINAL RESEARCH ARTICLES |
The Effect Of Melatonin On Cerebral And Carotid Artery Blood Flow In Rats
Dr.Selma Arzu VARDAR,a Dr.Gülay DURMUŞ ALTUN,b Dr.Mevlüt YAPRAK,a Dr.Mehmet Erdal VARDAR,c Dr.Ziya ÇUKUR,d Dr.Kadir KAYMAKa
aFizyoloji AD, bNükleer Tıp AD, cPsikiyatri AD, dDeneysel Araştırma Lab., Trakya Üniversitesi Tıp Fakültesi, EDİRNE
Objective: The aim of this study was to investigate the effect of varying concentrations of melatonin on cerebral and carotid ar-tery blood flow in adult rats.
Material and Methods: Adult male Sprague-Dawley rats were randomized into four (n=6) groups. Dynamic scintigraphic measurements were performed on the control group following rapid intravenous injection of Tc 99m HMPAO. Before scintigra-phy, a solvent containing NaCl 9%0 plus 1% ethanol without melatonin was administrated intraperitoneally to a vehicle group. The remaining groups received either 0.1g/kg or 100g/kg melatonin before dynamic scintigraphic measurements. Regions of interest (ROI’s) were hand-drawn over the brain, left ventri-cle, as well as the right and left carotid arteries in the rats. Time activity curves of these ROI’s were acquired. Brain retention indices (BRI), right carotid artery ratio (RCR), and left carotid artery ratio (LCR) values were determined.
Results: In comparison with controls, the BRI value was observed to be significantly lower in rats when melatonin was administrated at the physiological dose (0.1g/kg) (p=0.01). On the other hand, a pharmacological dose of melatonin (i.e. 100g/kg) did not re-sult in significant changes of BRI value when compared to con-trol and vehicle groups. In rats receiving melatonin at physio-logical dose, LCR and RCR values did not significantly differ from other groups. However, a pharmacological dose resulted in significantly higher LCR and RCR values.
Conclusion: The results suggested that the administration of mela-tonin at physiological dose reduces cerebral blood flow in rats. At the pharmacological dose, melatonin increases carotid artery blood flow without providing an increase in cerebral blood flow in rats.Keywords: Melatonin, cerebral blood flow, carotid artery, ratTurkiye Klinikleri J Med Sci 2004, 24:207-212
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