Influence of Ion Channel Blockers on Proliferation and Free Intracellular Ca²⁺ Concentration of Human Keratinocytes

The proliferation of in vitro cultivated keratinocytes from the HaCaT cell line while under the influence of different ion channel blockers, i.e. calcium channel blockers tetraethylammonium (TEA) and the nonspecific anion channel blocker 4′,4′-diisothiocyanato-stilbene-2-2′ disulfonic acid (DIDS) was investigated. There were changes in proliferation of the keratinocytes brought on by TEA and DIDS. It can be assumed that the effects of TEA on proliferated keratinocytes lead to a temporary arrest of cells in the G₁-phase of the cell cycle. The change in the extracellular K⁺ concentration ([K⁺]_e) had no influence on the proliferation of keratinocytes. During the entire course of investigations, the adding of DIDS leads to an increase in proliferation. Proliferation of keratinocytes is known to be greatly dependent on intracellular Ca²⁺ content ([Ca²⁺]_i). The blocking of ion channels with TEA or DIDS does not lead to a change in the free [Ca²⁺]_i. Also a change in the [K⁺]_e does not lead to a displacement of the [Ca²⁺]_i of keratinocytes.