translate English to French: Substitution of Na+ by Li+ in the medium caused a contraction which was dependent upon extracellular Ca2+, and which was accompanied by increased 45Ca uptake and increased Ca2+ content.
La substitution du Na+ du milieu par du Li+ produit une contraction indépendante du Ca2+ extracellulaire et accompagnée d'une augmentation de la captation du 45Ca et du contenu en Ca2+.