TY - JOUR AU - Goravanahally, Madhusudan P. AU - Sen, Aritro AU - Inskeep, Emmet K. AU - Flores, Jorge A. PY - 2007 DA - 2007/08/30 TI - PKCepsilon and an increase in intracellular calcium concentration are necessary for PGF2alpha to inhibit LH-stimulated progesterone secretion in cultured bovine steroidogenic luteal cells JO - Reproductive Biology and Endocrinology SP - 37 VL - 5 IS - 1 AB - The hypotheses that PKCepsilon is necessary for: 1) PGF2alpha to inhibit LH-stimulated progesterone (P4) secretion, and 2) for the expression of key prostaglandin synthesizing/metabolizing enzymes were tested in bovine luteal cells in which PKCepsilon expression had been ablated using a validated siRNA protocol. Steroidogenic cells from Day -6 bovine corpus luteum (CL) were isolated and transfected to reduce PKCepsilon expression after 48, 72 and 96 h. A third tested hypothesis was that an increase in intracellular calcium concentration ([Ca(2+)]i) is the cellular mechanism through which PGF2alpha inhibits luteal progesterone. The hypothesis was tested with two pharmacological agents. In the first test, the dose-dependent effects on raising the [Ca(2+)]i with the ionophore, A23187, on basal and LH-stimulated P4 secretion in cells collected from early (Day -4) and mid-cycle (Day -10) bovine CL was examined. In the second test, the ability of PGF2alpha to inhibit LH-stimulated P4 secretion in Day-10 luteal cells was examined under conditions in which an elevation in [Ca(2+)]i had been buffered by means of the intracellular calcium chelator, Bapta-AM. SN - 1477-7827 UR - https://doi.org/10.1186/1477-7827-5-37 DO - 10.1186/1477-7827-5-37 ID - Goravanahally2007 ER -