Effects of orphanin FQ On simple and norepinephrine-activated cardiac function in isolated rat heart / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of orphanin FQ (OFQ) on simple and norepinephrineactivated cardiac function in isolated rat heart.Methods Male SD rats aged 3-4 months weighing 250-280 g were anesthetized with intraperitoneal 25% urethane 1.4-1.8 ml.Their hearts were excised and passively perfused with K-H solutionin a Lanngendorff apparatus.A fluid-filled latex balloon was inserted into left ventricle for measurement of developed pressure.Left ventricular systolic pressure(LVSP),left ventricular end-diastofic pressure(LVEDP),left ventricular developed pressure(LVDP=LVSP-LVEDP),HR and±dp/dtmax were measured.Sixty isolated rat hearts were randomly divided into 10 groups(n=6 each)Ⅰ control group (group C);Ⅱ,Ⅲ,Ⅳ OFQ1,OFQ2,OFQ3 group--OFQ 10-6,10-7,10-8 mol/L were administered via perfusion system respectively;Ⅴ OFQ+UFP group--OFQ 10-6 mol/L+UFP-101 (all OFQ antagonist) 10-6 mol/L were administered;Ⅵ NE group--norepinephrine 10-5 mol/L;Ⅶ,Ⅷ,Ⅸ NE+OFQ groups--NE 10-5 mol/L+OFQ 10-6,10-7,10-8 mol/L were administered respectively;Ⅹ NE+OFQ+UFP group--NE 10-5 mol/L+OFQ 10-6mol/L+UFP-101 10-6mol/L.Results LVSP,LVDP and±dp/dtmax were significantly increased while HR was significantly decreased in the 3 OFQ groups as compared with control group.LVSP,LVDP±dp/dt max and HR were significantly increased in the 3 NE+OFQ groups as compared with NE group.Conclusion OFQ has positive inotropic action and negative chronotropic effect on the isolated rat heart.OFQ Can enhance the positive inotropic and chronotropic effect of NE on the heart.