White R D, Swick R A, Cheeke P R
J Toxicol Environ Health. 1983 Oct-Dec;12(4-6):633-40. doi: 10.1080/15287398309530455.
Effects of microsomal enzyme induction by phenobarbital (PB) injection (ip) and ingestion of Eucalyptus globulus foliage or phenothiazine (PT) on the toxicity of pyrrolizidine alkaloids (PA) or dried plant material of Senecio longilobus (SL) and Senecio jacobaea (SJ) were evaluated in rats. The oral median lethal doses (LD50) for a PA mixture extracted from SL at 72, 144, and 168 h post PA administration were approximately greater than 320, 190, and 160 mg/kg, respectively. Induction of mixed-function oxidase (MFO) activity by PB or dietary eucalyptus leaves resulted in only a marginal effect on the acute LD50, with no effective change at 168 h. The LD50 values at 72, 144, and 168 h for PB-treated rats were approximately 320, 190, and 160 mg/kg, and for eucalyptus treated rats approximately 127, 133, and 133 mg/kg, respectively. Dietary PT did not alter the toxicity of SJ but did cause reductions in feed intake and average daily gain. Supplemental cysteine increased (p less than 0.05) survival time in SJ-consuming rats, with a concomitant increase (p less than 0.05) in SJ ingestion, and caused slight increases in average daily gain. The simultaneous addition of cysteine and PT to an SJ-containing diet resulted in an increased (p less than 0.05) survival time over SJ and SJ + PT diet groups and a slight decrease in survival time compared to the SJ + cysteine group.
通过腹腔注射苯巴比妥（PB）以及摄入蓝桉树叶或吩噻嗪（PT）来诱导微粒体酶，进而评估其对大鼠体内吡咯里西啶生物碱（PA）或长叶千里光（SL）和欧洲千里光（SJ）干燥植物材料毒性的影响。PA混合物从SL中提取，在PA给药后72、144和168小时的经口半数致死剂量（LD50）分别约大于320、190和160毫克/千克。PB或日粮中的桉树叶对混合功能氧化酶（MFO）活性的诱导仅对急性LD50产生轻微影响，在168小时时无有效变化。PB处理组大鼠在72、144和168小时的LD50值分别约为320、190和160毫克/千克，桉树叶处理组大鼠的LD50值分别约为127、133和133毫克/千克。日粮中的PT未改变SJ的毒性，但确实导致采食量和平均日增重降低。补充半胱氨酸可增加（p小于0.05）食用SJ的大鼠的存活时间，同时增加（p小于0.05）SJ的摄入量，并使平均日增重略有增加。在含SJ的日粮中同时添加半胱氨酸和PT，与SJ和SJ + PT日粮组相比，存活时间增加（p小于0.05），但与SJ +半胱氨酸组相比，存活时间略有缩短。
