Production of leukotriene B4 by luteal tissues of sheep treated with prostaglandin F2 alpha.
Sheep were injected on Day 10 of the estrous cycle with a luteolytic dose of prostaglandin (PG) F2 alpha or injection vehicle. Corpora lutea were recovered at laparatomy 2, 4, 8, and 16 h following treatment. Portions of tissue were processed for light microscopy and analyzed for concentrations of leukotriene (LT) B4 and progesterone. There was a significant increase in LTB4 in tissues collected before evidence of either functional or structural regression (2 h); such levels were sustained. Tissues isolated 2 h after administration of PGF2 alpha and placed in short-term incubation produced considerable quantities of LTB4. Although no direct in vitro effect of PGF2 alpha on luteal production of LTB4 was demonstrated, it seems possible that lipoxygenase products of arachidonate metabolism, such as LTB4, could act as intermediates in the luteolytic mechanism of action of PGF2 alpha in vivo.
Steadman
L E
LE
Department of Animal Science, University of Wyoming, Laramie 82071.
Murdoch
W J
WJ
D000818:Animals; D003338:Corpus Luteum / Q000187:drug effects / Q000502:physiology*; D015237:Dinoprost / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D007700:Kinetics; D007975:Leukotriene B4 / Q000096:biosynthesis*; D012016:Reference Values; D012756:Sheep
D007975:Leukotriene B4; D015237:Dinoprost