Absence of physiological tolerance to cocaine in pregnant sheep.
Absence of physiological tolerance to cocaine in pregnant sheep.
复制标题
怀孕绵羊对可卡因缺乏生理耐受性。
DOI：
10.1080/714052758
复制
发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Anderson,KJ
中科院分区：
文献类型：
--
作者：
Burchfield,DJ;Hargrove,NL;Anderson,KJ
目的确定绵羊在怀孕期间重复施用可卡因是否会改变母体和胎儿的基础血流动力学状态，并确定这种可卡因暴露是否会改变随后对可卡因的血流动力学反应。 方法从妊娠第 75 天到第 128 天（足月 = 145 天），每天对 16 只怀孕羊施用可卡因或生理盐水。妊娠 128 天时，确定母体和胎儿的基础生理测量值，包括胎儿器官特异性血流量。然后每只实验母羊和对照母羊接受2 mg/kg的可卡因，并在接下来的30分钟内再次测量这些生理参数，以确定实验动物是否对可卡因的作用产生耐受性。结果治疗组之间的基础生理参数没有差异。同样，在急性注射可卡因后，两组的生理参数都以相似的方式做出反应。母羊服用可卡因后，两组均出现胎儿低氧血症。为了应对低氧血症，无论是动物第一次还是第53次接触可卡因，胎儿的大脑、心肌和肾上腺血流量都会增加，因此氧输送不会受到损害。结论对于本研究中测量的心血管参数，我们发现母羊或胎儿对可卡因没有耐受性。母体给予可卡因的急性血流动力学影响对于已接受超过 50 次的动物与首次接受可卡因的动物一样严重。
ObjectiveTo determine whether repetitive administration of cocaine to sheep during pregnancy altered basal hemodynamic states in the mother and fetus, and to determine whether this cocaine exposure would alter subsequent hemodynamic responses to cocaine.MethodsCocaine or saline was administered to 16 pregnant sheep daily from day 75 to day 128 of gestation (term = 145 days). At 128 days' gestation, maternal and fetal basal physiological measurements, including organ-specific blood flow in the fetus, were determined. Each experimental and control ewe then received cocaine 2 mg/kg and these physiological parameters were again measured over the next 30 min to determine whether the experimental animals had developed tolerance to the effects of cocaine.ResultsNo differences were seen in basal physiological parameters between treatment groups. Likewise, following an acute administration of cocaine, physiological parameters in both groups responded in a similar fashion. Fetal hypoxemia occurred in both groups after the ewe received cocaine. In response to hypoxemia, whether it was the animals' first or 53rd exposure to cocaine, fetal cerebral, myocardial and adrenal blood flow increased so that oxygen delivery was unimpaired.ConclusionsFor the cardiovascular parameters measured in this study, we found no tolerance to cocaine in the ewe or fetus. The acute hemodynamic effects of maternal cocaine administration were as severe for animals having received it more than 50 times as for those that received it for the first time.