Melatonin inhibits calcitonin gene-related peptide-induced vasodilation and increase in cAMP in rat middle cerebral arteries.
The action of melatonin to alter calcitonin gene-related peptide (CGRP)-mediated vasodilation and stimulation of adenylate cyclase activity in middle cerebral arteries of rats was investigated. Concentration-dependent dilation of the rat middle cerebral artery produced by CGRP (EC(50) of 9.4 x 10(-10) M) was significantly inhibited in the presence of 10(-8) M melatonin (EC(50) of 3.4 x 10(-9) M). In addition, CGRP (10(-7) M)-mediated increase in adenylate cyclase activity was also significantly attenuated by the receptor mediated action of melatonin. These results indicate that melatonin may interact with CGRP to regulate cerebral arterial tone.
Center for Molecular Physiology Research, Children's Research Institute, Department of Pediatrics, The George Washington University School of Medicine and Health Sciences, Washington, DC 20010, USA. mviswana@cnmc.org
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Viswanathan
D000262:Adenylyl Cyclases / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D015740:Calcitonin Gene-Related Peptide / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D020768:Middle Cerebral Artery / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014664:Vasodilation / Q000187:drug effects* / Q000502:physiology
D000975:Antioxidants; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D015740:Calcitonin Gene-Related Peptide; D008550:Melatonin