摘要:

This study examined the influence of the endothelium on metabolic and mechanical properties of porcine coronary arteries. Oxygen consumption rates (JO2) and lactate release (Jlac) under basal conditions were similar for intact (+E) and denuded (-E) rings. While passive tension was not different in2+E and -E arteries, the -E rings did develop a significant level of basal tone. With 50 mM KC1 stimulation, JO2and Jlacin both +E and -E arteries increased to similar levels, and developed force also was not different. While calculated total rates of ATP utilization (JATP) showed an increase in both +E and -E rings with 50 mM KCI stimulation, there were no differences attributable to the presence of the endothelium. In summary, the endothelium does not significantly alter the metabolic or mechanical properties of porcine coronary arteries, although it does appear to play a role in the suppression of basal tone.

ISSN:1062-3329    

DOI:10.3109/10623329409100970

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

This study investigates the sites of nitric oxide (NO) release on perivascular nerve stimulation (PNS) in organ bath experiments with isolated guinea pig pulmonary (PA) and iliac artery (IA). All the preparations were pretreated with indomethacin (10−5M), to exclude the effects of cyclo-oxygenase-generated eicosanoids. NG-nitro-L-arginine methyl ester (L-NAME, 10−6M) significantly augmented the PNS-induced adrenergic contraction and subsequently administered L-arginine (3×10−4M) reversed this augmentation in both arteries. In PA, endothelial denudation did not abolish but significantly attenuated this L-NAME-induced augmentation, while it abolished the augmentation in IA. In prostaglandin F2α-precontracted PA after blockade of both adrenergic and cholinergic effector responses, PNS induced tetrodotoxin (3×10−7M)-sensitive relaxation. This relaxation was attenuated by L-NAME (10−6M) and reversed by L-arginine (3×10−4M). But it was not abolished by endothelial denudation. On the other hand, PNS did not induce such relaxation in IA under the same conditions. The above effects of L-NAME were reproduced by bovine hemoglobin (10−5M), another NO inhibitor in both arteries pretreated with capsaicin (10−6M, 15 minutes).Thus, the suggested sites of NO release on PNS are both endothelium and perivascular nerves in PA, whereas it is only endothelium in IA.

ISSN:1062-3329    

DOI:10.3109/10623329409100971

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor