An Efficient Procedure for the Determination of Progesterone by Radioimmunoassay Applied to Bovine Peripheral Plasma

Hoffmann, Bernd; Kyrein, Hans Joachim; Ender, M. L.

doi:10.1159/000178317

Cited by 124 publications

(47 citation statements)

References 3 publications

(3 reference statements)

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“…Established RIA procedures were used for the assay of peripheral blood plasma progesterone (Hoffmann et al 1973) and the prostaglandin F2a metabolite PGFM (Kindahl et al 1976, Granströ m & Kindahl 1982.…”

Section: Canine Placental Prostaglandinsmentioning

confidence: 99%

Canine placenta: a source of prepartal prostaglandins during normal and antiprogestin-induced parturition

et al. 2010

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Expression of cyclooxygenase 2 (COX2, now known as PTGS2), prostaglandin E2 synthase (PTGES, PGES), and prostaglandin F2a synthase (PGFS), of the respective receptors PTGFR (FP), PTGER2 (EP2), and PTGER4 (EP4) and of the progesterone receptor (PGR, PR) was assessed by real-time PCR, immunohistochemistry (IHC), or in situ hybridization (ISH) in utero/placental tissue samples collected from three to five bitches on days 8-12 (pre-implantation), 18-25 (post-implantation), and 35-40 (mid-gestation) of pregnancy and during the prepartal luteolysis. Additionally, ten mid-pregnant bitches were treated with the antiprogestin aglepristone (10 mg/kg bw (2!/24 h)); ovariohysterectomy was 24 and 72 h after the second treatment. Plasma progesterone and 15-ketodihydro-PGF2a (PGFM) concentrations were determined by RIA. Expression of the PGR was highest before implantation and primarily located to the endometrium; expression in the placenta was restricted to the decidual cells. PTGS2 was constantly low expressed until mid-gestation; a strong upregulation occurred at prepartal luteolysis concomitant with an increase in PGFM. PGFS was upregulated after implantation and significantly elevated through early and mid-gestation. PTGES showed a gradual increase and a strong prepartal upregulation. PTGFR, PTGER2, and PTGER4 were downregulated after implantation; a gradual upregulation of PTGFR and PTGER2 occurred towards parturition. ISH and IHC co-localized PGFS, PTGFR, PTGES, and PTGS2 in the trophoblast and endometrium. The changes following application of aglepristone were in the same direction as those observed from mid-gestation to prepartal luteolysis. These data suggest that the prepartal increase of PGF2a results from a strong upregulation of PTGS2 in the fetal trophoblast with the withdrawal of progesterone having a signalling function and the decidual cells playing a key role in the underlying cell-to-cell crosstalk.

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Section: Canine Placental Prostaglandinsmentioning

confidence: 99%

Canine placenta: a source of prepartal prostaglandins during normal and antiprogestin-induced parturition

et al. 2010

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“…In all experiments, the basal steroidogenic capacity of freshly isolated luteal cells was tested using dbcAMP-treated cells as positive control. The cell culture medium was finally collected and stored at K20 8C for radioimmunoassay (RIA), which was performed as described previously (Hoffmann et al 1973).…”

Section: Canine Primary Luteal Cellsmentioning

confidence: 99%

Prostaglandin E2 functions as a luteotrophic factor in the dog

Kowalewski¹,

Fox²,

Gram³

et al. 2013

Reproduction

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The luteal phase in dogs is governed by many poorly understood regulatory mechanisms. Functioning of the corpus luteum (CL) is unaffected by hysterectomy. Recently, the role of prostaglandins in regulating canine CL function was addressed suggesting a luteotrophic effect of prostaglandin E 2 (PGE 2 ) during the early luteal phase. However, compelling functional evidence was lacking. The potential of PGE 2 to stimulate steroidogenesis was tested in canine primary luteal cells isolated from developing CL of non-pregnant dogs. In addition, the luteal expression of prostaglandin transporter (PGT) and steroidogenic acute regulatory protein (STAR) was demonstrated and characterized in CL from non-pregnant bitches during the course of dioestrus as well as from pregnant animals during the preimplantation, post-implantation and mid-gestation periods of pregnancy and during luteolysis; the luteal expression of PGE 2 receptors (EP2 and EP4) has been investigated at the protein level throughout pregnancy. Our findings show that PGE 2 is an activator of STAR expression in canine luteal cells from early luteal phase, significantly up-regulating STAR promoter activity and protein expression resulting in increased steroidogenesis. The 3bHSD (HSD3B2) and P450scc (CYP11A1) expression remained unaffected by PGE 2 treatment. The expression of PGT was confirmed in CL during both pregnancy and dioestrus and generally localized to the luteal cells. After initial up-regulation during the earlier stages of the CL phase, its expression declined towards the luteal regression. Together with the demonstration of EP2 and EP4 throughout pregnancy, and the decline in EP2 at prepartum, our findings further support our hypothesis that intra-luteal PGE 2 may play an important role in regulating progesterone secretion in the canine CL.

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“…Sensitivity of the assay was 1-6 pg/tube. Progesterone was determined as originally described by Hoffmann et al (1973). The antiserum was raised in a rabbit against 1 la-hydroxyprogesteronehemisuccinate-bovine serum albumin.…”

Section: Introductionmentioning

confidence: 99%

Concentrations of vitamin A, -carotene and vitamin E in individual bovine follicles of different quality

Schweigert¹,

Zücker²

1988

Reproduction

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Summary. The degree of atresia of the follicle had no influence on the intrafollicular concentrations of \g=b\-carotene, vitamin E and cholesterol. This might result from the passive transfer of these substances from blood to follicular fluid bound to high density lipoproteins. However, concentrations of vitamin A in follicular fluid were significantly (P < 0\m=.\001) influenced by follicle quality, with highest concentrations (0\m=.\32 \ g = m \ g / m l ) in non-atretic follicles and lowest values (0\m=.\15 \g=m\g/ml) in greatly atretic follicles. The higher concentrations of vitamin A in healthy follicles might be due to a local conversion of \ g = b \ \ x = r e q -\ carotene into vitamin A in follicular structures. By influencing hormone and protein synthesis, vitamin A may have a potential for local modulation of follicular development and therefore be one of the factors controlling recruitment, selection and growth of the dominant follicle in cattle.

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An Efficient Procedure for the Determination of Progesterone by Radioimmunoassay Applied to Bovine Peripheral Plasma

Cited by 124 publications

References 3 publications

Canine placenta: a source of prepartal prostaglandins during normal and antiprogestin-induced parturition

Canine placenta: a source of prepartal prostaglandins during normal and antiprogestin-induced parturition

Prostaglandin E2 functions as a luteotrophic factor in the dog

Concentrations of vitamin A, -carotene and vitamin E in individual bovine follicles of different quality

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