Increase in 85Sr Uptake by Elevated Concentration of K in Guinea Pig Taenia Coli

In taenia coli, 40 mM K induced a tonic contraction accompanied by an increased oxygen consumption. When Ca in the bathing medium was replaced by Sr, 40 mM K developed little tension but increased oxygen consumption to a similar degree as that in normal medium (1). Although the movement of Ca and its possible relationship to tension development and also to oxygen consumption have been reported in taenia coli in the presence of 40 mM K (2, 3), there are few data concerning a movement of Sr ion in smooth muscle. In the present report 85Sr uptake by taenia coli was studied in comparison with 45Ca movement.