The study was designed to examine the aglepristone (RU534) mechanisms affecting the corpora lutea (CL) lifespan in pseudopregnant rabbits. Aglepristone (10 mg/kg b.w.) was injected subcutaneously twice at either early- or mid-luteal phase (Days 3 and 4, or Days 8 and 9, respectively) after induction of ovulation with GnRH (Day 0). Corpora lutea and uteri, explanted at days 6 and 11, were evaluated for immunohistochemistry and Western blotting of progesterone (PR) and estrogen (ER) receptors, cyclooxygenase 1 (COX1), COX2, and PGE2-9-ketoreductase (PGE2-9-K) enzymatic activities, and progesterone, PGF2 alpha, and PGE2 in vitro synthesis. Independent of luteal stage, aglepristone prolonged the functional luteal phase by 3 Days over that of controls as assessed by blood progesterone profiles. Aglepristone decreased protein for ER during both luteal-stages in CL and uteri. Progesterone receptor protein was decreased by RU354 at Days 6 in the uterus and at Days 11 in CL, whereas RU534 increased PR at Days 11 in uteri. In the CL, RU534 enhanced progesterone production at Days 6 and 11, whereas it decreased PGF2 alpha and increased PGE2 at Day 11. In the uteri, RU534 decreased PGF2 alpha and increased PGE2 synthesis at both days. COX2 and PGE2-9K activities were decreased by RU534 in the CL at Day 11, whereas in the uteri COX2 increased and PGE2-9-K decreased at Days 6 and 11. In conclusion, these data on aglepristone effects suggest that progesterone has a regulatory role on luteal function through direct and uterine-mediated mechanisms in pseudopregnant rabbits. (C) 2013 Elsevier B.V. All rights reserved.
Aglepristone (RU534) effects on luteal function of pseudopregnant rabbits: steroid receptors, enzymatic activities, and hormone productions in corpus luteum and uterus
DALL'AGLIO, Cecilia;BRECCHIA, Gabriele;MARANESI, MARGHERITA;POLISCA, Angela;BOITI, Cristiano;Zerani M.
2013
Abstract
The study was designed to examine the aglepristone (RU534) mechanisms affecting the corpora lutea (CL) lifespan in pseudopregnant rabbits. Aglepristone (10 mg/kg b.w.) was injected subcutaneously twice at either early- or mid-luteal phase (Days 3 and 4, or Days 8 and 9, respectively) after induction of ovulation with GnRH (Day 0). Corpora lutea and uteri, explanted at days 6 and 11, were evaluated for immunohistochemistry and Western blotting of progesterone (PR) and estrogen (ER) receptors, cyclooxygenase 1 (COX1), COX2, and PGE2-9-ketoreductase (PGE2-9-K) enzymatic activities, and progesterone, PGF2 alpha, and PGE2 in vitro synthesis. Independent of luteal stage, aglepristone prolonged the functional luteal phase by 3 Days over that of controls as assessed by blood progesterone profiles. Aglepristone decreased protein for ER during both luteal-stages in CL and uteri. Progesterone receptor protein was decreased by RU354 at Days 6 in the uterus and at Days 11 in CL, whereas RU534 increased PR at Days 11 in uteri. In the CL, RU534 enhanced progesterone production at Days 6 and 11, whereas it decreased PGF2 alpha and increased PGE2 at Day 11. In the uteri, RU534 decreased PGF2 alpha and increased PGE2 synthesis at both days. COX2 and PGE2-9K activities were decreased by RU534 in the CL at Day 11, whereas in the uteri COX2 increased and PGE2-9-K decreased at Days 6 and 11. In conclusion, these data on aglepristone effects suggest that progesterone has a regulatory role on luteal function through direct and uterine-mediated mechanisms in pseudopregnant rabbits. (C) 2013 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
