硫喷妥钠对α受体激动剂引起的离体兔肺动脉收缩的增强作用。

Thiopental potentiation of isolated rabbit pulmonary artery contractions with alpha receptor agonists.

作者信息

Fukuda S, Inomata I, Tsuji T, Takeshita H

出版信息

Anesthesiology. 1984 Mar;60(3):187-92. doi: 10.1097/00000542-198403000-00003.

DOI:10.1097/00000542-198403000-00003

Abstract

The effects of thiopental sodium on the adrenergic neuroeffector junction were studied in isolated rabbit pulmonary arteries. Basal tension was not altered by thiopental (2 X 10(-5) and 10(-4) M) but was increased by high concentrations of thiopental (5 X 10(-4) M). Thiopental (10(-4) and 5 X 10(-4) M) potentiated contractions induced by transmural electrical stimulation. Contractile responses to exogenously applied low concentrations of norepinephrine (NE) were potentiated by thiopental (2 X 10(-5), 10(-4) and 5 X 10(-4) M), whereas those to high concentrations were not altered. In strips previously incubated in 1-[7,8-3H]-NE (10(-7) M), the release of [3H] induced by transmural stimulation (5 Hz) was not altered by thiopental (10(-4) and 5 X 10(-4) M). Potentiation by thiopental (10(-4) M) of the responses to transmural stimulation was not affected by prior application of cocaine or hydrocortisone. Contractions induced by alpha receptor agonists (phenylephrine and methoxamine) were potentiated by thiopental (10(-4) M), while those induced by acetylcholine were not altered. Contractile responses to potassium chloride were attenuated by thiopental (10(-4) M). Amobarbital sodium and pentobarbital sodium (10(-4) M, respectively) attenuated contractions induced by NE. It may be concluded that thiopental specifically increases the responsiveness of postsynaptic alpha receptors to NE.

摘要

在离体兔肺动脉中研究了硫喷妥钠对肾上腺素能神经效应器接头的影响。硫喷妥（2×10⁻⁵和10⁻⁴M）不改变基础张力，但高浓度硫喷妥（5×10⁻⁴M）可使其升高。硫喷妥（10⁻⁴和5×10⁻⁴M）增强经壁电刺激诱导的收缩。硫喷妥（2×10⁻⁵、10⁻⁴和5×10⁻⁴M）增强对外源性低浓度去甲肾上腺素（NE）的收缩反应，而对高浓度NE的反应则无改变。在预先用1-[7,8-³H]-NE（10⁻⁷M）孵育的肌条中，硫喷妥（10⁻⁴和5×10⁻⁴M）不改变经壁刺激（5Hz）诱导的[³H]释放。硫喷妥（10⁻⁴M）对经壁刺激反应的增强不受预先应用可卡因或氢化可的松的影响。α受体激动剂（去氧肾上腺素和甲氧明）诱导的收缩被硫喷妥（10⁻⁴M）增强，而乙酰胆碱诱导的收缩则无改变。硫喷妥（10⁻⁴M）减弱对氯化钾的收缩反应。异戊巴比妥钠和戊巴比妥钠（分别为10⁻⁴M）减弱NE诱导的收缩。可以得出结论，硫喷妥特异性增加突触后α受体对NE的反应性。