EFFECTS OF DELTAMETHRIN ON CATECHOLAMINE SECRETION OF BOVINE CHROMAFFIN CELLS

The effects of the pyrethroid deltamethrin (D) on catecholamine secret ion of cultured bovine chromaffin cells were investigated in vitro usi ng high performance liquid chromatography (HPLC). Spontaneous release of catecholamines was increased by 10 mu M and 100 mu M D. This increa se could partially be prevented by the simultaneous use of 2 mu M tetr odotoxin (TTX), which reduced the increase by 10 mu M D of catecholami ne secretion by 90% and that of 100 mu M D by 50%. TTX 2 mu M alone di d not alter the spontaneous release in comparison to controls. Medulla ry chromaffin cells consist of two cell groups, one secreting mainly e pinephrine (E), the other norepinephrine (NE). The ratio between the s pontaneously secreted catecholamines E and NE was increased after trea tment with D, indicating a dominant effect on E secreting cells.