Effects of deltamethrin on catecholamine secretion of bovine chromaffin cells

The effects of the pyrethroid deltamethrin (D) on catecholamine secretion of cultured bovine chromaffin cells were investigated in vitro using high performance liquid chromatography (HPLC). Spontaneous release of catecholamines was increased by 10 microM and 100 microM D. This increase could partially be prevented by the simultaneous use of 2 microM tetrodotoxin (TTX), which reduced the increase by 10 microM D of catecholamine secretion by 90% and that of 100 microM D by 50%. TTX 2 microM alone did not alter the spontaneous release in comparison to controls. Medullary chromaffin cells consist of two cell groups, one secreting mainly epinephrine (E), the other norepinephrine (NE). The ratio between the spontaneously secreted catecholamines E and NE was increased after treatment with D, indicating a dominant effect on E secreting cells.