Effects of adrenomedullin on the cardiac performance and coronary flow in an isolated perfused rat heart model.
The effect of adrenomedullin (AM) on the cardiac performance and coronary flow were studied in an isolated perfused rat heart model based on the modified Langendorff method. The heart rate (HR), electrocardiogram (ECG), left ventricular contraction (LVC) (dP/dt), and coronary flow (CF) were measured before and after the application of AM. The effect of AM on the coronary flow was examined in the model with and without endothelial degradation, using different inhibitors such as N(G)-nitro-L-arginine, glibenclamide, and indomethacin. The present results indicated that AM increased HR and CF, but decreased LVC significantly, while it had no effect on ECG. The vasodilatory effect of AM was discussed in views of endothelial-dependence due to nitric oxide and K+ channel activation.
Amatyakul
S
S
Department of Physiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. medspr@hotmail.com
Patumraj
S
S
Niimi
H
H
D053607:Adrenomedullin; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D002317:Cardiovascular Agents / Q000494:pharmacology*; D003326:Coronary Circulation / Q000187:drug effects*; D000242:Cyclic AMP / Q000502:physiology; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004562:Electrocardiography / Q000187:drug effects; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005905:Glyburide / Q000494:pharmacology; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D007213:Indomethacin / Q000494:pharmacology; D017136:Ion Transport / Q000187:drug effects; D008297:Male; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D019335:Nitroarginine / Q000494:pharmacology; D010455:Peptides / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism; D015221:Potassium Channels / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D015290:Second Messenger Systems / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology; D016277:Ventricular Function, Left / Q000187:drug effects
D000959:Antihypertensive Agents; D002317:Cardiovascular Agents; D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D010455:Peptides; D015221:Potassium Channels; D014665:Vasodilator Agents; D053607:Adrenomedullin; D019335:Nitroarginine; D009569:Nitric Oxide; D000242:Cyclic AMP; D019001:Nitric Oxide Synthase; D011188:Potassium; D005905:Glyburide; D007213:Indomethacin