text: Prostaglandin E1, E2, STA2 (a stable analogue of thromboxane A2), 17-phenyl-trinor-PGE2 (an EP1-selective agonist) and sulprostone (an EP3-selective agonist) inhibited the HVA Ca2+ current (HVA ICa) dose-dependently, and the rank order of potency to inhibit << HVA Ca2+ channels >> was sulprostone>PGE2, [[ PGE1 ]]>STA2>>17-phenyl-trinor-PGE2.