Oestrogen and progesterone concentrations in peripheral blood in pregnant red foxes (Vulpes vulpes)

Bonnin, M.; Mondain-Monval, M.; Dutourné, B.

doi:10.1530/jrf.0.0540037

Cited by 25 publications

(7 citation statements)

References 7 publications

(19 reference statements)

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“…Sampling frequency in the present study may have been inadequate to define an implantation surge of estradiol, as in the red fox (Bonnin et al 1978b), or a prepartum rise in estradiol, as in the domestic dog (Concannon et al 1975), the domestic cat (Verhage et al 1976), the western spotted skunk (Ravindra and Mead 1984), and the puma (Puma concolor) (Bonney et al 1981). Other canivores, such as the mink (Pilbeam et al 1979) and red fox (Bonnin et al 1978b), do not show a prepartum estradiol rise.…”

Section: Discussionmentioning

confidence: 76%

“…Other canivores, such as the mink (Pilbeam et al 1979) and red fox (Bonnin et al 1978b), do not show a prepartum estradiol rise. A larger sample and more frequent sampling during the gestative phase may reveal differences in estradiol profiles between pregnant and pseudopregnant bears, as well as between successful and unsuccessful pregnancies.…”

Section: Discussionmentioning

confidence: 88%

“…1975Concannon et ,al. , 1977 wolf (Canis lupus): Seal et al 1979; red fox (Vulpes vulpes): Bonnin et al 1978b) and some mustelids that exhibit delayed implantation (ferret (Mustela putorius) : Heap and Hammond 1974; European badger (Meles meles): Bonnin et al 1978a), pseudopregnancy, as measured by luteal activity and serum progesterone concentrations, lasts as long as normal pregnancy. Evidence of pseudopregnancy among bears is limited to a captive Hokkaido brown bear that was isolated from male bears throughout the year, yet exhibited changes in progesterone concentrations virtually identical to those in four pregnant individuals, and therefore probably spontaneously ovulated and formed corpora lutea (Tsubota et al 1987).…”

Section: Discussionmentioning

confidence: 99%

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Endocrine and electrophoretic profiles during pregnancy and nonpregnancy in captive female black bears

Hellgren¹,

Vaughan²,

Gwazdauskas³

et al. 1991

Can. J. Zool.

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We collected blood samples from captive adult female black bears (Ursus americanus) at 10-day intervals during September–March in 1987–1988 and 1988–1989 (6 bears/year) in Virginia. Ten of 12 bears hibernated for an average of 92 days. Serum progesterone concentrations slowly increased from 2 to 7 ng/mL during October and November, then increased 2- to 3-fold 58 ± 5 days before parturition in five bears that produced cubs. After the implantation peak, progesterone gradually declined, reaching undetectable levels 1–2 days postpartum. Similar but more variable progesterone profiles were observed in five of seven bears that did not produce any observed cubs. Progesterone was also assayed in 38 active wild black bears to relate to reproductive status in the den. Results suggested that pseudopregnancy, implantation failure, or fetal resorption may occur in black bears. Mean serum estradiol-17β concentrations were 18.5 ± 0.7 (SE) pg/mL in captive bears, with pregnant bears showing no change between implantation and parturition. Polyacrylamide gel electrophoresis of serum proteins was not a reliable indicator of pregnancy.

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Section: Discussionmentioning

confidence: 76%

Section: Discussionmentioning

confidence: 88%

Section: Discussionmentioning

confidence: 99%

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Endocrine and electrophoretic profiles during pregnancy and nonpregnancy in captive female black bears

Hellgren¹,

Vaughan²,

Gwazdauskas³

et al. 1991

Can. J. Zool.

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“…E2 changes in this period are, therefore, suspected to be involved in parturition. A prepartum rise in E2 was reported in the domestic dog [5], the domestic cat [25], the western spotted skunk [17] and the puma [1], but not in the red fox [2] and the mink [16]. However, this discrepancy among carnivore species has not been explained well.…”

Section: Discussionmentioning

confidence: 95%

Serum Progesterone and Estradiol-17.BETA. Concentrations in Captive and Free-Ranging Adult Female Japanese Black Bears (Ursus thibetanus japonicus).

Sato

Tsubota

Yamamoto

et al. 2000

The Journal of Veterinary Medical Science

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ABSTRACT. Progesterone (P4) and estradiol-17β (E2) concentrations were measured in serum samples obtained from 23 captive and 23 freeranging adult female Japanese black bears. We then determined the relationship between changes in these sex steroid hormones and pregnancy. In all captive bears, which included animals of both known and unknown reproductive status, serum P 4 concentrations were low from April to July, then tended to become higher after August. The levels then became much higher still in November and December, but returned to low levels in March. Serum P 4 concentrations in eight captive pregnant bears, which had parturitions the following spring, increased gradually from August (0.5-2.4 ng/ml) to October (0.9-3.6 ng/ml), and achieved significantly higher maximum levels in December (7.2-18.0 ng/ml). Thereafter, serum P 4 concentrations tended to decrease (3.5-6.4 ng/ml in January and 0.3-0.7 ng/ml in March). In all captive bears, serum E 2 concentrations varied from April to October but showed low levels in November and December, and became high in January. Serum E 2 concentrations in the eight pregnant bears were high in May (95.6-191.4 pg/ml) and varied from August to October (35.6-143.3 pg/ml). Subsequently, serum E 2 concentrations in December dropped to significantly lower minimum levels (5.3-11.9 pg/ml) and increased again in January (67.6-153.1 pg/ml). Among the free-ranging bears, the data on serum P 4 concentrations in eight bears led to expectations of pregnancy, whereas serum E2 concentrations showed no distinct evidence related to pregnancy. These results, particularly in captive pregnant bears, indicate that a marked increase of P 4 in December might be accompanied by reactivation of the corpus luteum preceding implantation. Furthermore, changes in E 2 concentrations suggested the possibility that a decline in December and an increase in January are associated with implantation and parturition, respectively.-KEY WORD: bear, estradiol-17β, pregnancy, progesterone.

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“…Data on the reproductive physiology and endocrinology of the fox are scarce, and the available information is limited to the ovarian steroid hormones in peripheral plasma (Moller, 1973(Moller, , 1974aMondain-Monval, Dutourné, Bonnin, Canivenc & Scholler, 1977;Bonnin, Mondain-Monval & Dutourné, 1978;Mondain-Monval, Bonnin, Scholler & Canivenc, 1979;Meiler, Aursjo & Sjaastad, 1980). There appears to be no information for these furbearing animals on the changes in plasma concentrations of luteinizing hormone (LH) during pro-oestrus and oestrus, which take place once a year, usually in March and April.…”

Section: Introductionmentioning

confidence: 99%

Temporal relationships between hormonal concentrations and the electrical resistance of the vaginal tract of blue foxes (Alopex lagopus) at pro-oestrus and oestrus

Møller¹,

Mondain-Monval²,

Smith³

et al. 1984

Reproduction

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Summary. During pro-oestrus, baseline LH concentrations for 9 vixens (pooled data) ranged from 0\m=.\8 to 5\m=.\3ng/ml. In each vixen, baseline levels were interrupted by elevations of LH ranging from 3\m=.\1to 10\m=.\4 ng/ml. A major preovulatory LH surge was detected in all the vixens. The LH peak ranged from 13\m=.\5to 73\m=.\0 ng/ml with an average of 27\m=.\8 \m=+-\18\m=.\8(s.d.) ng/ml. Plasma LH concentrations declined to a basal level of 1\m=.\3\ m=+-\ 1\ m=. \ 0 ng/ml within 48 h of the peak value. The duration of the LH surge was 1\p=n-\3 days. The LH peak occurred 1 or 2 days before any sexual receptivity was observed. All the vixens were mated twice 2\p=n-\5 days after the LH peak; 8 conceived. Plasma concentrations of oestradiol-17\g=b\increased gradually during the last 6\p=n-\7 days before oestrus and reached maximum values (124\p=n-\373pg/ml) at the time of the preovulatory LH peak. The first significant increase in plasma progesterone concentration occurred simultaneously with the LH peak. During oestrus (normally 3\p=n-\5 days), progesterone levels rose steeply, attaining a mean concentration of 57\m=.\0 \m=+-\ 17\m=.\5 ng/ml when the vixens went out of heat. Androstenedione and testosterone values changed similarly, both increasing at the beginning of pro-oestrus and reaching maximum values (805\p=n-\1879pg/ml and 328\p=n-\501 pg/ml respectively) 1 day before to 1 day after the oestradiol-17\g=b\peak.The electrical resistance of the vaginal tract increased rapidly during the last 2\p=n-\3 days of pro-oestrus, reaching a maximum value (300\p=n-\640\g=W\)~2 days after the oestradiol-17\g=b\peak that corresponded with the onset of sexual receptivity. Towards the end of oestrus, the values fell to 100\p=n-\200\ g=W\ .

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Oestrogen and progesterone concentrations in peripheral blood in pregnant red foxes (Vulpes vulpes)

Cited by 25 publications

References 7 publications

Endocrine and electrophoretic profiles during pregnancy and nonpregnancy in captive female black bears

Endocrine and electrophoretic profiles during pregnancy and nonpregnancy in captive female black bears

Serum Progesterone and Estradiol-17.BETA. Concentrations in Captive and Free-Ranging Adult Female Japanese Black Bears (Ursus thibetanus japonicus).

Temporal relationships between hormonal concentrations and the electrical resistance of the vaginal tract of blue foxes (Alopex lagopus) at pro-oestrus and oestrus

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