铊（I）对心肌和骨骼肌的毒性。

The toxicity of thallium(I) to cardiac and skeletal muscle.

作者信息

Hughes M N, Man W K, Whaler B C

出版信息

Chem Biol Interact. 1978 Oct;23(1):85-97. doi: 10.1016/0009-2797(78)90043-1.

Abstract

The effects of (a) partial or complete replacement of K+ by Tl+ in saline perfusing isolated rat heart and diaphragm preparations and (b) pulse injections of high concentrations of Tl+ or K+, have been studied. The immediate effect of Tl+ resembles that of higher concentrations of K+ and may reflect its more rapid penetration into the tissue. Tl+ appears to replace K+ on a 1:1 basis to an extent dependent upon the relative abundance of the two cations in the perfusion solution. However, analysis of diaphragm preparations after perfusion with salines containing increasing Tl+ but constant [K+ + Tl+] showed a related and progressive increase in total cation content. This effect, which was not seen in the presence of constant high (normal) K+ concentrations, may reflect an increase of the intracellular space brought about by the thallium. Functional effects of Tl+ were (a) preferential block of the phrenic nerve or neuromuscular junction over the muscle fibre and (b) transient but marked acceleration of cardiac frequency following pulse injections, which may be of value in analysing the pacemaker mechanism of the heart. In both tissues Tl+ is eventually toxic and probably irreversibly so.

摘要

研究了以下两种情况的影响

(a) 在灌注离体大鼠心脏和膈肌标本的盐溶液中，用铊离子（Tl⁺）部分或完全替代钾离子（K⁺）；(b) 脉冲注射高浓度的Tl⁺或K⁺。Tl⁺的即时效应类似于较高浓度K⁺的效应，可能反映了其更快地渗透到组织中。Tl⁺似乎以1:1的比例替代K⁺，替代程度取决于灌注溶液中这两种阳离子的相对丰度。然而，在用含Tl⁺浓度增加但[K⁺ + Tl⁺]恒定的盐溶液灌注膈肌标本后进行分析，结果显示总阳离子含量呈相关的渐进性增加。在高（正常）K⁺浓度恒定的情况下未观察到这种效应，这可能反映了铊导致细胞内空间增加。Tl⁺的功能效应为：(a) 与肌纤维相比，膈神经或神经肌肉接头优先被阻断；(b) 脉冲注射后心脏频率短暂但显著加快，这可能对分析心脏的起搏机制有价值。在这两种组织中，Tl⁺最终都是有毒的，而且可能是不可逆的。