Effect of dose of prostaglandin F(2alpha) on steroidogenic components and oligonucleosomes in ovine luteal tissue.
To determine whether prostaglandin (PG) F(2alpha) had a dose-dependent effect upon secretion of progesterone, oligonucleosome formation, or loss of luteal weight, ewes on Day 9 or 10 of the estrous cycle were administered 0, 3, 10, or 30 mg PGF(2alpha) per 60 kg BW (i.v.), and luteal tissue was collected 9 and 24 h after injection. All doses of PGF(2alpha) decreased (P < 0. 05) concentrations of progesterone in sera by 9 h; however, in ewes treated with 3 mg PGF(2alpha), concentrations of progesterone were similar to control values at 24 h and higher (P < 0.05) than those in the 10- or 30-mg groups. Concentrations of progesterone in sera over all dose levels were highly correlated to luteal concentrations of mRNA encoding steroidogenic acute regulatory protein (P < 0.001), cytochrome P450 side-chain cleavage (P < 0.02), and 3beta-hydroxysteroid dehydrogenase (P < 0.01). Corpora lutea collected at 24 h from ewes treated with the 10- and 30-mg doses of PGF(2alpha) weighed less (P < 0.05) than those from controls. Oligonucleosomes were not present in luteal tissues from control ewes. Surprisingly, all doses of PGF(2alpha)-induced oligonucleosomes in a majority of animals at 9 h and in a majority of ewes treated with 10 and 30 mg of PGF(2alpha) at 24 h. In conclusion, 3 mg of PGF(2alpha) per 60 kg BW transiently decreased serum concentrations of progesterone and induced oligonucleosome formation, but did not result in reduced luteal weight. The 10- and 30-mg doses of PGF(2alpha) decreased secretion of progesterone and induced oligonucleosome formation and luteolysis.
Juengel
J L
JL
Animal Reproduction and Biotechnology Laboratory, Colorado State University, Fort Collins, Colorado 80526, USA.
Haworth
J D
JD
Rollyson
M K
MK
Silva
P J
PJ
Sawyer
H R
HR
Niswender
G D
GD
D015096:3-Hydroxysteroid Dehydrogenases / Q000096:biosynthesis; D000818:Animals; D003338:Corpus Luteum / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D004247:DNA / Q000032:analysis / Q000096:biosynthesis / Q000302:isolation & purification; D015237:Dinoprost / Q000096:biosynthesis / Q000494:pharmacology*; D004971:Estrus / Q000502:physiology; D005260:Female; D003341:Luteolysis / Q000187:drug effects; D009707:Nucleosomes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D009929:Organ Size / Q000187:drug effects; D010750:Phosphoproteins / Q000096:biosynthesis; D011374:Progesterone / Q000096:biosynthesis; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D011974:Receptors, LH / Q000096:biosynthesis; D012756:Sheep; D013256:Steroids / Q000096:biosynthesis*; D000098682:Steroidogenic Acute Regulatory Protein
D009707:Nucleosomes; D010750:Phosphoproteins; D012333:RNA, Messenger; D011974:Receptors, LH; D013256:Steroids; D000098682:Steroidogenic Acute Regulatory Protein; D011374:Progesterone; D004247:DNA; D015237:Dinoprost; D015096:3-Hydroxysteroid Dehydrogenases