HOME HELP CONTACT US SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Silvia, W J Articles by Brockman, J A Search for Related Content PubMed Articles by Silvia, W J Articles by Brockman, J A

The first objective was to describe and evaluate the relationship between the ability of oxytocin to stimulate the activity of phospholipase (PL) C and its ability to stimulate the release of prostaglandin (PG) F₂ in ovine endometrial tissue. Caruncular endometrial tissue was collected from ovariectomized ewes after completion of an 11-day steroid replacement protocol. In experiment 1, explants were incubated either in the presence (10^–6 M) or absence of oxytocin for 0, 1, 3, 10, 30 or 100 min to examine the time-course for activation of PLC and release of PGF₂ in response to oxytocin. An increase in the activity of PLC was detected at 3 min while an increase in the release of PGF₂ was not detected until 10 min (P<0·05). In experiment 2, explants were incubated in the presence of various oxytocin analogues (10^–6 M) to compare their abilities to activate PLC and release PGF₂. Oxytocin and three receptor angonists stimulated the activity of PLC and the release of PGF₂ (P<0·05) while two oxytocin receptor antagonists had no effect on either response. In experiment 3, explants were incubated in the presence of oxytocin or arginine vasopressin at 10^–9 to 10^–6 M to establish dose–response curves for the activation of PLC and release of PGF₂. For both hormones, significant increases (P<0·05) in the release of PGF₂ were observed at 10^–8 M while increases in PLC activity were not detected until 10^–7 M was used. In experiment 4, explants were pretreated with either U-73122 (an inhibitor of PLC activity) or U-73343 (an inactive analogue of U-73122). Explants were then treated with control medium, oxytocin or AlF₄^–. Both oxytocin and AlF₄^– stimulated the activity of PLC and the release of PGF₂ (P<0·05). U-73122 blocked the ability of oxytocin to stimulate the release of PGF₂ (P<0·05) but had no effect on its ability to stimulate the activity of PLC (P>0·1). Based on the results from these experiments, the role of PLC in mediating the stimulatory effect of oxytocin on the release of PGF₂ remains unclear.

The second objective was to evaluate the role of diacylglycerol (DAG) in mediating the stimulatory effect of oxytocin on endometrial secretion of PGF₂. In experiment 5, explants were incubated in vitro with varying doses of two DAG analogues. Both analogues stimulated the release of PGF₂ at 10^–6 M (P<0·05), the highest dose tested. Corresponding inactive control compounds had no stimulatory effect. In experiment 6, explants were incubated with two synthetic DAGs and two indole-derived analogues of DAG. The indole derivatives stimulated the release of PGF₂. The synthetic DAGs were less effective in stimulating the release of PGF₂ at the doses tested. In experiment 7, explants were preincubated with R59022 [GenBank] or LiCl. R59022 [GenBank] enhanced both the basal and oxytocin-stimulated released of PGF₂ (P=0·07). LiCl promoted an increase in the accumulation of inositol trisphosphate (P<0·05) but had no effect on the release of PGF₂ (P>0·5). These data indicate that DAG stimulates release of PGF₂ from ovine endometrial tissue and may mediate the stimulatory effect of oxytocin on release of PGF₂.

Journal of Endocrinology (1994) 141, 481–490

This article has been cited by other articles:

				C. V. Bishop and F. Stormshak Nongenomic Action of Progesterone Inhibits Oxytocin-Induced Phosphoinositide Hydrolysis and Prostaglandin F2{alpha} Secretion in the Ovine Endometrium Endocrinology, February 1, 2006; 147(2): 937 - 942. [Abstract] [Full Text] [PDF]

				E. Madore, N. Harvey, J. Parent, P. Chapdelaine, J. A. Arosh, and M. A. Fortier An Aldose Reductase with 20alpha -Hydroxysteroid Dehydrogenase Activity Is Most Likely the Enzyme Responsible for the Production of Prostaglandin F2alpha in the Bovine Endometrium J. Biol. Chem., March 21, 2003; 278(13): 11205 - 11212. [Abstract] [Full Text] [PDF]

				P. D. Burns, J. O.B. Mendes Jr., R. S. Yemm, C. M. Clay, S. E. Nelson, S. H. Hayes, and W. J. Silvia Cellular Mechanisms by Which Oxytocin Mediates Ovine Endometrial Prostaglandin F2{alpha} Synthesis: Role of Gi Proteins and Mitogen-Activated Protein Kinases Biol Reprod, October 1, 2001; 65(4): 1150 - 1155. [Abstract] [Full Text] [PDF]

				G. Gimpl and F. Fahrenholz The Oxytocin Receptor System: Structure, Function, and Regulation Physiol Rev, April 1, 2001; 81(2): 629 - 683. [Abstract] [Full Text] [PDF]

				D. J Skarzynski, Y. Uenoyama, J. Kotwica, and K. Okuda Noradrenaline Stimulates the Production of Prostaglandin F2{alpha} in Cultured Bovine Endometrial Cells Biol Reprod, February 1, 1999; 60(2): 277 - 282. [Abstract] [Full Text] [PDF]

				M. Uzumcu, G. T. Braileanu, K. G. Carnahan, T. E. Ludwig, and M. A. Mirando Oxytocin-Stimulated Phosphoinositide Hydrolysis and Prostaglandin F Secretion by Luminal Epithelial, Glandular Epithelial, and Stromal Cells from Pig Endometrium. I. Response of Cyclic Pigs on Day 16 Postestrus Biol Reprod, November 1, 1998; 59(5): 1259 - 1265. [Abstract] [Full Text]