Beneficial effects of intracoronary nicardipine on hypoxic myocardium.
Regional effects of intracoronary administration of nicardipine, a dihydropyridine derivative with calcium blocking activity, were studied in 13 open-chest dogs. Hypoxic, constant-flow perfusion was done in the area supplied by the distal left anterior descending artery. The 5-min regional hypoxic perfusion did not result in significant alterations in either heart rate or aortic pressure in 6 control dogs perfused with original Krebs-Henseleit solution (KHS), which was deoxygenized by mixed gas (95%N2 and 5%CO2), and in 7 dogs perfused with nicardipine-containing (0.2 mg/dl) KHS. A transmural biopsy after 5 min of perfusion revealed a less severe metabolic deterioration in nicardipine-treated dogs than in control dogs, as indicated by a higher ATP content (2.84 +/- 0.43 vs. 2.23 +/- 0.45 mumol/g, wet weight). The sequence of regional contractile deterioration was not different between the 2 groups. In conclusion, regional nicardipine administration showed a myocardial protective effect which was not mediated by afterload reduction in the whole heart.
Department of Medicine, School of Medicine, Keio University, Tokyo, Japan.
R
R
Miyamori
Y
Y
Nakamura
H
H
Mori
T
T
Miyazaki
S
S
Kojima
S
S
Abe
M
M
Takahashi
S
S
Hattori
D000227:Adenine Nucleotides / Q000378:metabolism; D000818:Animals; D003327:Coronary Disease / Q000378:metabolism / Q000503:physiopathology*; D003331:Coronary Vessels; D004285:Dogs; D004734:Energy Metabolism / Q000187:drug effects*; D007261:Infusions, Intra-Arterial; D009200:Myocardial Contraction / Q000187:drug effects*; D009529:Nicardipine / Q000008:administration & dosage / Q000494:pharmacology*
D000227:Adenine Nucleotides; D009529:Nicardipine