Epidermal growth factor (EGF), tumor promoter 12- O-tetradecanoylphorbol 13-acetate (TPA) and calcium ionophore A23187 increase cytoplasmic free calcium and stimulate arachidonic acid release and PGE 2/6-keto PGF 1α production in cultured porcine thyroid cells

Abstract

Epidermal growth factor (EGF), 12- O-tetradecanoylphorbol 13-acetate (TPA) and calcium ionophore A23187 increase cytoplasmic free calcium ([Ca 2+] i) and stimulate arachidonic acid release and production of PGE 2 and 6-keto PGF 1α an end metabolite of PGI 2, in cultured porcine thyroid cells. Addition of EGF, TPA or A23187 to the cells loaded with fura-2, a fluorescent Ca 2+ indicator, causes an immediate increase in [Ca 2+] i which is the earliest event after mitogen stimulation. This [Ca 2+] i response occurs immediately, reaching a maximum within several seconds. EGF, TPA and A23187 stimulate arachidonic acid release and PGE 2 and 6-keto PGF 1α production; the maximum effects are obtained after 2–4 h incubation. EGF, TPA and A23187 increase [Ca 2+] i and then stimulate arachidonic acid release and PG production.