Pregnancy diagnosis in the domestic horse through direct urinary estrone conjugate analysis

Evans, Kymberlee; Kasman, L. H.; Hughes, John P.; Couto, Marcelo; Lasley, Bill L.

doi:10.1016/0093-691x(84)90489-8

Cited by 36 publications

(13 citation statements)

References 10 publications

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“…Interestingly, the increase in 17OH-progesterone concentrations appears to precede that of progesterone by a week but peak at concentrations one third those of progesterone. The current data also confirm a concomitant increase in androstenedione (Daels et al 1998) which, though one tenth the concentration of 17OH-progesterone, is highly correlated with it and likely provides substrate for the increased secretion of estrone sulphate seen at this point in pregnancy (Evans et al 1984, Hyland et al 1984. The detection of testosterone in some mares during this interval is also consistent with the stimulation of D4 steroids in general.…”

Section: Discussionsupporting

confidence: 74%

The dynamic steroid landscape of equine pregnancy mapped by mass spectrometry

Legacki¹,

Scholtz²,

Ball³

et al. 2016

Reproduction

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Liquid chromatography-tandem mass spectrometry (LC-MS/MS) allowed comprehensive analysis of various steroids detectable in plasma throughout equine gestation. Mares (nZ9) were bled serially until they foaled. Certain steroids dominated the profile at different stages of gestation, clearly defining key physiological and developmental transitions. The period (weeks 6-20) coincident with equine chorionic gonadotropic (eCG) stimulation of primary corpora lutea and subsequent formation of secondary luteal structures was defined by increased progesterone, 17OH-progesterone and androstenedione, all D4 steroids. The 5a-reduced metabolite of progesterone, dihydroprogesterone (DHP) paralleled progesterone secretion at less than half the concentration until week 12 of gestation when progesterone began to decline but DHP concentrations continued to increase. DHP exceeded progesterone concentrations by week 16, clearly defining the luteo-placental shift in pregnane synthesis from primarily ovarian to primarily placental. The period corresponding to the growth of fetal gonads was defined by increasing dehydroepiandrosterone and pregnenolone (D5 steroids) concentrations from week 14, peaking at week 34 and declining to term. Metabolites of DHP (including allopregnanolone) dominated the steroid profile in late gestation, some exceeding DHP by weeks 13 or 14 and near term by almost tenfold. Thus D4 steroids dominated during ovarian stimulation by eCG, inversion of the ratio of progesterone: DHP (increasing 5a-pregnanes) marked the luteo-placental shift, D5 steroids defined fetal gonadal growth and 5a-reduced metabolites of DHP dominated the steroid profile in mid-to late-gestation. Comprehensive LC-MS/MS steroid analysis provides opportunities to better monitor the physiology and the progress of equine pregnancies, including fetal development.

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Section: Discussionsupporting

confidence: 74%

The dynamic steroid landscape of equine pregnancy mapped by mass spectrometry

Legacki¹,

Scholtz²,

Ball³

et al. 2016

Reproduction

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“…The first increase of conjugated oestrogens commencing after day 36 of pregnancy is of ovarian origin (Terqui and Palmer 1979;Daels et al 1991); the second increase commences between days 50 and 60 and results from the production of conjugated and free oestrogens by the placenta. (Nett et al 1973Kindahl et al 1982;Hyland et al 1984;Evans et al 1983). In a different manner to that of other domestic mammals, the placental oestrogen production in Mean values (ice .…”

Section: Introductionmentioning

confidence: 99%

Investigations into the Course of Progesterone‐, Oestrogen‐ and eCG‐concentrations During Normal and Impaired Pregnancy in the Mare*

Hoffmann¹,

Gentz²,

Failing³

1996

Reprod Domestic Animals

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“…Concentrations of non-specific progesterone metabolites remained above l·0µg/mg creatinine throughout the remainder of the collection period. Urinary oestrone conjugates fell to basal concentrations (15-55 ng/mg creatinine) for 35 days after the ovulatory nadir in non-specific progesterone metabolites and then rose abruptly to l-45pg/mg creatinine, which is a characteristic signal of pregnancy in mares (Evans et al, 1984). During the first 5 days of urine collection, which coincided with the preovulatory oestrone conjugate increases, M17GL displayed behaviour associated with oestrus and was witnessed being successfully mounted on Days 3-5 of collection.…”

Section: Assessment Of Ovarian Functionmentioning

confidence: 99%