Kanakis C, Pouget J M, Rosen K M
Circulation. 1976 Apr;53(4):703-7. doi: 10.1161/01.cir.53.4.703.
Systolic time intervals (STI) were measured in ten healthy male volunteers before and after intravenous (i.v.) administration of 25 mug/kg delta-9-tetrahydrocannabinol (delta-9-THC). Mean +/- SEM heart rate increased 32 +/- 7 beats/min, while systolic and diastolic blood pressures were unchanged after delta-9-THC. Total electromechanical systole lengthened 17 +/- 4.2 msec, left ventricular ejection time (LVETc) prolonged 24 +/- 4.0 msec and pre-ejection period (PEP) shortened 17 +/- 5.1 msec after delta-9-THC. All of these changes were significant (P less than 0.01). In nine other subjects who underwent prior beta adrenergic blockade, similar but less marked changes were noted in heart rate, blood pressure, and STI after delta-9-THC. The shortening of PEP after delta-9-THC was only 9 msec (NS) in beta blocked subjects. Thus, delta-9-THC significantly increased heart rate, shortened PEP and prolonged LVETc without any change in afterload. Beta adrenergic blockade prevented significant shortening of PEP and blunted other responses. These findings suggest that delta-9-THC enhanced cardiac performance. Partial inhibition of this effect was achieved with prior beta adrenergic blockade.
在10名健康男性志愿者静脉注射25微克/千克的Δ⁹-四氢大麻酚（Δ⁹-THC）之前和之后测量了收缩期时间间期（STI）。平均±标准误心率增加了32±7次/分钟，而在给予Δ⁹-THC后收缩压和舒张压未发生变化。总电机械收缩期延长了17±4.2毫秒，左心室射血时间（LVETc）延长了24±4.0毫秒，射血前期（PEP）在给予Δ⁹-THC后缩短了17±5.1毫秒。所有这些变化均具有显著性（P<0.01）。在另外9名先前接受过β肾上腺素能阻滞剂治疗的受试者中，给予Δ⁹-THC后，心率、血压和STI出现了相似但不太明显的变化。在β受体阻滞剂治疗的受试者中，给予Δ⁹-THC后PEP的缩短仅为9毫秒（无显著性差异）。因此，Δ⁹-THC显著增加了心率，缩短了PEP并延长了LVETc，而心脏后负荷没有任何变化。β肾上腺素能阻滞剂阻止了PEP的显著缩短并减弱了其他反应。这些发现表明，Δ⁹-THC增强了心脏功能。预先给予β肾上腺素能阻滞剂可部分抑制这种作用。
