title: Role of luteal prostaglandins in the control of bovine corpus luteum functions.
abstract: Current and emerging concepts on regulation of bovine corpus luteum function by various metabolites of arachidonic acid are reviewed. A series of experiments are presented which support the concept that prostacyclin (PGI2), a metabolite of arachidonic acid via the cyclooxygenase pathway, plays a luteotropic role, and that products of the lipoxygenase pathway of arachidonic acid metabolism, particularly 5-hydroxyeicosatetraenoic acid (5-HETE), play a luteolytic role in the function of the bovine corpus luteum (CL). These ideas are supported by the following findings: injection of PGI2 directly into CL at mid-cycle produced a prolonged increase in peripheral plasma concentrations of progesterone; PGI2 stimulated synthesis of progesterone by dispersed luteal cells; synthesis of PGI2 by luteal cells was greatest during the period of early CL development (d 5 and 10), and diminished as the CL aged unless pregnancy ensued, causing a maintenance of the CL and synthesis of PGI2; administration of indomethacin, a blocker of synthesis of prostaglandin by the cyclooxygenase pathway, twice daily on d 4 to 6 of the estrous cycle inhibited CL development and caused a reduction in cycle length, suggesting the presence of a luteotropic prostaglandin; oxytocin administration twice daily on d 4 through 6 inhibited CL development and was accompanied by a 50% reduction in luteal synthesis of PGI2 by CL collected on d 7; large quantities of 5-HETE were found in luteal tissue; the addition of 5-HETE to dispersed luteal cells inhibited synthesis of progesterone and PGI2, while production of PGF2 alpha was unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000818:Animals; D002417:Cattle; D003338:Corpus Luteum / Q000187:drug effects* / Q000378:metabolism; D011464:Epoprostenol / Q000494:pharmacology*; D005260:Female; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology*; D008186:Luteolytic Agents / Q000494:pharmacology
chemical_list: D006893:Hydroxyeicosatetraenoic Acids; D008186:Luteolytic Agents; D011464:Epoprostenol