Proteins secreted by Day-16 to -18 bovine conceptuses extend corpus luteum function in cows

Knickerbocker, J.J.; Thatcher, W.W.; Bazer, Fuller W.; Drost, Maarten R.; Barron, Donald H.; Fincher, K. B.; Roberts, R. M.

doi:10.1530/jrf.0.0770381

Cited by 176 publications

(74 citation statements)

References 30 publications

(37 reference statements)

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“…Our hypothesis that prostaglandin substrate may be diverted from PGF to other prostaglandins is, therefore, incorrect. In sheep and cattle, intrauterine infusion of secretory proteins from the early conceptus extends the length of dioestrus Knickerbocker et al, 1986;Vallet et al, 1988). Measurement of prostaglandin concentrations revealed that these proteins inhibited endometrial synthesis of PGF but not of PGE-2 (Vallet et al, 1988).…”

Section: Discussionmentioning

confidence: 99%

Prostaglandin production by horse embryos and the effect of co-culture of embryos with endometrium from pregnant mares

Watson

Sertich²

1989

Reproduction

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Summary. Embryos, endometrial biopsies, and uterine lavage fluid were collected from pregnant and non-pregnant mares 14 days after ovulation. Embryos were cultured for 20\m=.\5h with and without endometrial tissue from pregnant mares, and endometrial tissue was cultured alone. Endometrial content of PGF tended to be higher (P = 0\m=.\06) in non-pregnant than in pregnant mares, but the amount of PGF released from tissue during culture was similar for pregnant and non-pregnant mares. Lavage fluid from non-pregnant mares also tended (P= 0\m=.\08) to contain higher concentrations of PGF. Co\ x=req-\ incubation of embryos with endometrium from pregnant mares significantly (P = 0\m=.\01) lowered concentrations of PGF in medium. Tissue concentrations and release of PGE-2 and 6-keto-PGF-1\g=a\were similar in endometrial samples from pregnant and non\x=req-\ pregnant mares and prostaglandin production was unaffected by the presence of an embryo during incubation. Horse embryos released all three prostaglandins during a 20\m=.\5-hincubation.

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Section: Discussionmentioning

confidence: 99%

Prostaglandin production by horse embryos and the effect of co-culture of embryos with endometrium from pregnant mares

Watson

Sertich²

1989

Reproduction

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“…The blood samples were refrigerated at 4°C for 24h and then centrifuged (1200 x g for 15 minutes) for separation of serum. Serum was frozen and stored at -20 º C until radioimmunoassay for P4 determination (Knickerbocker et al, 1986 performed and intra-assay coefficients of variation were 7.6, 8.2, and 5.3, with inter-assay coefficient of variation of 7.9 and assay sensitivity of 0.3ng/ml.…”

Section: Methodsmentioning

confidence: 99%

Conception rate in Holstein cows treated with GnRH or hCG on the fifth day post artificial insemination during summer

Beltran

Vasconcelos

2008

Arq. Bras. Med. Vet. Zootec.

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Lactating Holstein cows (n=158), at 213±112 days in milking and averaging 26±9kg of milk per day, were randomly assigned to one of three treatment groups: control (CG, n=52, saline), GnRH (GG, n=55, 100µg gonadorelin), and hCG (HG, n=51, 2500IU) given five days after artificial insemination (AI). Rectal temperature was taken at the moment of AI and blood samples were collected five, seven, and 12 days after AI. Pregnancy was determined between 42 and 49 days after AI. Concentration of progesterone (P4) in serum (ng/ml, mean±SE) for CG, GG, and HG were, respectively, 2.7±0.4, 2.5±0.4, and 3.2±0.5 on day 5; 4.8±0.4, 4.2±0.4, and 5.7±0.5 on day 7; and 5.2±0.4, 6.9±0.4, and 8.5±0.5 on day 12 after AI. P4 concentration had proportional increase in serum between days 5 and 7 after AI (CG: 178%, GG: 168%, and HG: 178%), suggesting that the treatments did not induce a luteotropic effect on the existing corpus luteum (CL). Concentrations of P4 increased between days 7 and 12 in cows treated with GnRH and hCG (GG: 164%, and HG: 149%, P<0.01); but not in control cows (GC: 18%, P=0.31), suggesting that a new CL was formed. Treatments with GnRH or hCG increased conception rates in cows with rectal temperature below 39.7°C (CG: 10.1%, n=26, GG: 36.8%, n=27; and HG: 32.8%, n=21), but not in cows with rectal temperature above 39.7°C (CG: 15.2%, n=26; GG: 17.8%, n=28; and HG: 24.4%, n=30). These data suggest that high body temperature masked the positive impact of treatment with GnRH or hCG on day 5 after AI on conception.Keywords: dairy cow, conception, progesterone, hCG, GnRH (GC, n=52, salina); GnRH (GG, n=55, 100mcg de gonadorelina); e hCG (GH, n=51, 2500UI de hCG) RESUMO Vacas da raça Holandesas em lactação (n=158) aos 213±112 dias de lactação e produção de 26±9kg leite/dia, foram aleatoriamente distribuídas em três grupos: controle

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“…The intra-and inter-assay coefficients of variation were 4.2 and 7.5%, respectively. Plasma concentrations of progesterone were measured in a single assay using procedures described previously (Knickerbocker et al, 1986). Intra-assay coefficient of variation was 6%.…”

Section: Introductionmentioning

confidence: 99%

Follicular dynamics, plasma metabolites, hormones and insulin-like growth factor I (IGF-I) in lactating cows with positive or negative energy balance during the preovulatory period

Lucy¹,

Beck²,

Staples³

et al. 1992

Reprod. Nutr. Dev.

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Summary ― The effect of dietary energy balance (EB) on growth of ovarian follicles was tested. Cows (n = 9) were fed a high energy diet (HE diet; positive EB; n = 4) or switched to a low energy diet (LE diet; negative EB; n = 5) during the preovulatory period. Non-esterified fatty acids (NEFA) were greater in cows fed the LE diet. Concentrations of luteinizing hormone (LH) were similar in HE and LE cows. However, the growth of preovulatory follicles in cows fed the LE diet was 50% that of cows fed the HE diet. Insulin-like growth factor-I (IGF-I) in plasma was less in LE-fed cows compared with HE-fed cows, and plasma IGF-I was positively correlated to estrogen: progesterone ratio in follicular fluid of dominant follicles. In summary, slower follicular growth in cows fed an LE diet occurred despite normal plasma LH and coincided with reduced IGF-I and elevated NEFA in plasma.

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Proteins secreted by Day-16 to -18 bovine conceptuses extend corpus luteum function in cows

Cited by 176 publications

References 30 publications

Prostaglandin production by horse embryos and the effect of co-culture of embryos with endometrium from pregnant mares

Prostaglandin production by horse embryos and the effect of co-culture of embryos with endometrium from pregnant mares

Conception rate in Holstein cows treated with GnRH or hCG on the fifth day post artificial insemination during summer

Follicular dynamics, plasma metabolites, hormones and insulin-like growth factor I (IGF-I) in lactating cows with positive or negative energy balance during the preovulatory period

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