Cardiovascular responses to catecholamines and interactions with endothelin-1 and adenine nucleosides in the pericardium of the dog heart.
The pericardial fluid may accumulate endogenous regulatory agents, such as catecholamines, endothelin or adenine nucleosides. However, very little information is available on the cardiovascular effects of intrapericardial (i.p.) catecholamines and their interaction with the endogenous endothelins and adenine nucleosides. The cardiovascular effects of increasing doses of i.p.- administered dopamine boluses (0.06-8 micromol/kg, n = 8) were studied in the in situ canine heart: systemic blood pressure, heart rate and left ventricular dP/dt were recorded, and pericardial infusate samples were obtained to measure the changes in endothelin-1 (ET-1), adenosine and inosine levels (enzyme-linked immunosorbent assay and high-performance liquid chromatography methods, respectively). The responses to i.p. dopamine were compared with the effects of i.p. norepinephrine boluses (0.004-0.5 micromol/kg, n = 8). Dopamine elicited dose-dependent increases of heart rate (P < 0.01), and the highest dose of dopamine resulted in significant elevation in dP/dt and blood pressure (P < 0.01) with a nearly twofold increase of i.p. ET-1 (from 14.3 +/- 0.1 pg/mL to 26.1 +/- 0.1 pg/mL, P < 0.02) and a more than threefold augmentation of i.p. adenosine (from 2.9 +/- 0.5 microM to 11.1 +/- 3.0 microM, P < 0.05), but not of inosine levels. Similar responses were obtained with i.p. norepinephrine. The results confirm that i.p. catecholamines exert significant hemodynamic effects and modulate ET-1 and adenosine release from the heart. However, the pattern of catecholamine actions initiated from the pericardium may characteristically differ from that of intravascular ones.
Kékesi
Violetta
V
Department of Cardiovascular Surgery, Semmelweis University, Budapest, Hungary. vkekesi@hermes.sote.hu
Toma
Ildikó
I
Nagy
Andrea
A
Rusvai
Miklós
M
Barát
Erzsébet
E
Huszár
Eva
E
Juhász-Nagy
Alexander
A
D000241:Adenosine / Q000378:metabolism*; D000818:Animals; D001794:Blood Pressure; D004285:Dogs; D004298:Dopamine / Q000008:administration & dosage / Q000378:metabolism*; D019332:Endothelin-1 / Q000378:metabolism*; D006339:Heart Rate; D006439:Hemodynamics; D007275:Injections, Intravenous; D007288:Inosine / Q000378:metabolism*; D009638:Norepinephrine / Q000008:administration & dosage / Q000378:metabolism*; D010496:Pericardium / Q000378:metabolism*; D015854:Up-Regulation; D016277:Ventricular Function, Left; D017725:Ventricular Pressure
D019332:Endothelin-1; D007288:Inosine; D000241:Adenosine; D004298:Dopamine; D009638:Norepinephrine