The effects of calcium and magnesium on the response of intestinal smooth muscle to drugs

Open Access
Publisher Website
Google Scholar
Abstract
1 . The sensitivity of the longitudinal muscle of the guinea-pig ileum to muscarinic drugs producing contraction depends on optimum concentrations of calcium and magnesium. It can also be reduced by changes in sodium concentration and osmolality. 2 . The rubidium efflux response to these same drugs is insensitive to any of these changes in the external medium. 3 . Raised calcium or magnesium concentration has the effect of largely annulling the differences in structure-activity relationships of the two responses as they exist in optimal media. 4 . The effects are explained in terms of a labile coupling process between a single receptor and the contractile process compared with a stable coupling process of the efflux process.

This publication has 4 references indexed in Scilit: