Sustained dilatation of large coronary artery by alpha-human atrial natriuretic peptide in conscious dogs: a comparison with nitroglycerin.
The effects of alpha-human atrial natriuretic peptide (alpha-hANP) on the coronary circulation were compared with those of nitroglycerin in 16 conscious dogs chronically instrumented with a pair of miniature sonomicrometers and an electromagnetic flow probe placed on the left circumflex coronary artery. alpha-hANP (1 and 10 micrograms) and nitroglycerin (0.1, 1 and 10 micrograms) were administered intracoronarily via a cannula implanted in the proximal left circumflex coronary artery. Both alpha-hANP and nitroglycerin dose dependently increased the coronary diameter and coronary blood flow. Although alpha-hANP (10 micrograms) and nitroglycerin (1 microgram) dilated the large coronary artery to almost the same extent (92 +/- 10 vs. 98 +/- 8 microns), the time course of the dilating action differed; the peak dilatation occurred at 5.6 +/- 0.8 and 0.9 +/- 0.07 min (P less than 0.01), and full recovery occurred at 31.5 +/- 3.8 and 5.5 +/- 1.3 min (P less than 0.01) after alpha-hANP and nitroglycerin, respectively. Topical application of alpha-hANP (50 micrograms) to the epicardial coronary artery of three anesthetized open-chest dogs did not affect the coronary diameter and coronary blood flow, while nitroglycerin (50 micrograms) increased both variables. Thus, intracoronary alpha-hANP dilates the large coronary artery more gradually and more sustainedly than nitroglycerin does.
Adachi
H
H
Research Institute of Angiocardiology, Faculty of Medicine, Kyushu University, Japan.
Tomoike
H
H
Nishijima
H
H
Egashira
S
S
Nakamura
M
M
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects*; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D005996:Nitroglycerin / Q000494:pharmacology*; D014664:Vasodilation / Q000187:drug effects*
D009320:Atrial Natriuretic Factor; D005996:Nitroglycerin