Mármol F, Puig-Parellada P, Forn J
Unitat de Farmacologia, Terapèutica i Farmacologia Clínica, Facultat de Medicina, Universitat de Barcelona, Spain.
Eur J Pharmacol. 1991 Oct 15;203(2):181-6. doi: 10.1016/0014-2999(91)90713-z.
We studied the effects of lithium chloride, given i.p. in doses of 0.05, 1, 2, 4 and 8 mEq/kg twice daily for 14 days, on preparations of guinea pig myenteric plexus. The effects of lithium added to isolated myenteric plexus preparations derived from chronically treated animals showed that relatively low lithium concentrations produced a statistically significant decrease in the force of contraction, this effect being concentration-dependent. 3-Isobutyl-1-methylxanthine (IBMX) induced a statistically significant inhibition, between 30 and 50%, of the lithium effects. cAMP levels in animals treated chronically with lithium were studied, using an isotopic displacement technique. Our results show that only the highest dose of lithium (8 mEq/kg per day) significantly decreased basal levels of cAMP. In the presence of IBMX, low doses of lithium (1 mEq/kg per day) induced a very significant decrease in cAMP levels, but the inhibition remained constant, approximately 30-35%, at doses from 2 mEq/kg per day. In guinea pig myenteric plexus preparations from acutely treated animals, our results show a direct relationship between lithium concentration and inhibition of the cAMP accumulation induced by IBMX.
我们研究了腹腔注射氯化锂（剂量为0.05、1、2、4和8毫当量/千克，每日两次，共14天）对豚鼠肠肌丛制备物的影响。将锂添加到来自长期处理动物的离体肠肌丛制备物中的作用表明，相对低的锂浓度会使收缩力产生统计学上显著的降低，这种作用具有浓度依赖性。3 - 异丁基 - 1 - 甲基黄嘌呤（IBMX）对锂的作用产生了30%至50%的统计学上显著的抑制。使用同位素置换技术研究了长期用锂处理的动物中的环磷酸腺苷（cAMP）水平。我们的结果表明，只有最高剂量的锂（每天8毫当量/千克）显著降低了cAMP的基础水平。在存在IBMX的情况下，低剂量的锂（每天1毫当量/千克）使cAMP水平非常显著地降低，但在每天2毫当量/千克及以上的剂量时，抑制作用保持恒定，约为30% - 35%。在急性处理动物的豚鼠肠肌丛制备物中，我们的结果显示锂浓度与对IBMX诱导的cAMP积累的抑制之间存在直接关系。
