Dissecting the functional role of different isoforms of the L-type Ca2+ channel.

There currently exist a great number of different mouse lines in which the activity of a particular gene of interest has been inactivated or enhanced. However, it is also possible to insert specific mutations in a gene so that the pharmacological sensitivity of the gene product is altered. An example of such an approach shows how the abolition of the sensitivity of an L-type Ca(2+) channel isoform to dihydropyridines allows the investigation of the physiological role of these channels in different tissues.