The contractile activity of cardiac and smooth muscles may be reduced by calcium antagonists (calcium channel blockers). Their tissue selectivity that is observed in functional studies may be related to characteristics of the drug, properties of the tissue and nature of the stimulus. This paper illustrates some of these factors, considering the postnatal changes in the sensitivity of cardiac contractility to calcium channel blockers and their difference in potency between cardiac and vascular tissue and within arteries.
Godfraind, T., Morel, N., & Wibo, M. (1993). Pharmacological Control of Calcium Channels and Muscle Contractility. Biomedical Research, 14(Suppl 2), 65-70. https://hdl.handle.net/2078.5/145114 (Original work published 1993)