Failure of prostaglandin F/sub 2/. cap alpha. to cause luteal regression in ewes after destruction of ovarian follicles by x-irradiation

Journal Article · Mon Sep 01 04:00:00 EDT 1975 · Biol. Reprod.; (United States)

DOI:https://doi.org/10.1095/biolreprod13.2.126· OSTI ID:7120473

Hixon, J E; Gengenbach, D R; Hansel, W

The hypothesis that estradiol-17..beta.. may play a role in prostaglandin F/sub 2/..cap alpha.. (PGF/sub 2/..cap alpha..)-induced luteolysis was tested in ewes following selective destruction of ovarian follicles by x-irradiation. The effects of two injections of (1) 7 mg PGF/sub 2/..cap alpha.., (2) 750 ..mu..g estradiol benzoate (E/sub 2/B) and (3) 7 mg PGF/sub 2/..cap alpha.. + 750 ..mu..g E/sub 2/B were compared in sham and x-irradiated ewes. Treatment of sham-irradiated ewes with PGF/sub 2/..cap alpha.. resulted in luteolysis in all 5 treated ewes, as judged by a fall in the plasma progesterone concentration to non-detectable levels (less than 0.2 ng/ml) by 54 h after the first injection. In contrast, luteolysis was not observed in 4 of 5 x-irradiated ewes following treatment with PGF/sub 2/..cap alpha.., as indicated by plasma progesterone levels greater than 1.60 ng/ml 96 h after the first injection and corpus luteum weights in excess of 535 mg. Luteolysis was observed in the fifth animal of this group, ewe No. 20, in which plasma progesterone fell to non-detectable levels and a corpus luteum of 203 mg was observed at autopsy. The mean plasma estradiol concentration ranged between 4 and 9 pg/ml in sham-irradiated, PGF/sub 2/..cap alpha..-treated ewes, but fell to non-detectable levels before treatment with PGF/sub 2/..cap alpha.. in all x-irradiated ewes except No. 20 in which levels as high as 11.6 pg/ml were observed. A large luteinized, cystic follicle was observed at autopsy in ewe No. 20. These observations suggest that destruction of ovarian follicles to remove the primary source of estradiol reduced the effectiveness of PGF/sub 2/..cap alpha.. as a luteolytic agent.

• Research Organization: Cornell Univ., Ithaca, NY
• OSTI ID: 7120473
• Journal Information: Biol. Reprod.; (United States), Journal Name: Biol. Reprod.; (United States) Vol. 13:2; ISSN BIREB
• Country of Publication: United States
• Language: English

Related Subjects

560152* -- Radiation Effects on Animals-- Animals
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BODY
DOMESTIC ANIMALS
ELECTROMAGNETIC RADIATION
ESTRADIOL
ESTRANES
ESTROGENS
FEMALE GENITALS
GONADS
HORMONES
HYDROXY COMPOUNDS
IONIZING RADIATIONS
KETONES
MAMMALS
ORGANIC COMPOUNDS
ORGANS
OVARIES
PREGNANES
PROGESTERONE
PROSTAGLANDINS
RADIATION EFFECTS
RADIATIONS
RUMINANTS
SHEEP
STEROID HORMONES
STEROIDS
VERTEBRATES
X RADIATION