Release of endothelial mediators and sympathetic transmitters at different coronary flow rates in rabbit hearts.

摘要: 1. The release of three endothelial mediators, namely, endothelial-derived relaxing factor (EDRF), prostacyclin (PGI2) and endothelin, two sympathetic neurotransmitters, noradrenaline neuropeptide Y (NPY), from resting or sympathetically stimulated rabbit Langendorff hearts was investigated at normal elevated coronary flow. nerves to the were 5 Hz for 30 s cardiac effluent analysed nitrite (metabolite EDRF) with electron paramagnetic resonance spectrometry, 6-keto-PGF1 alpha PGI2) gas chromatography/mass endothelin- NPY-like immunoreactivity radioimmunoassay, purines liquid chromatography. 2. During perfusion flow (35 +/- 1.4 ml min-1) concentration 0.15 0.02 microM, that 0.74 0.08 nM, endothelin-like 0.18 0.01 pM. Nerve stimulation augmented 76 8 99 10 pmol (3 min)-1 (P less than 0.05), but did not affect immunoreactivity. also facilitated outflow by 52 11 19 7 fmol min)-1, respectively. 3. Elevation 79 3.2 min-1 concentrations nitrite, immunoreactivity, implying their outflows augmented. Sympathetic further augment mediators increased 62 12%, in comparison Perfusion heart uptake blocker desipramine (5 microM) completely abolished promoting effecting on during stimulation. 4. These data indicate an increase perfused is paralleled a corresponding facilitation formation EDRF, endothelin. Such elevation mediator does nerve stimulation-induced transmitters heart.