Progesterone and conceptus-derived factors important for conceptus survival and growth

Lonergan, P.; Forde, Niamh; Spencer, Thomas E.

doi:10.21451/1984-3143-ar867

Cited by 9 publications

(10 citation statements)

References 102 publications

(99 reference statements)

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“…As expected, the IFNAR2 receptor, JAK1 , STAT1 and STAT2 cascade and IRF9 regulatory factor were upregulated on Days 14 and 18 following AI in pregnant cows in comfort; however, no difference was observed in all IFN pathway genes of pregnant cows under heat stress. The increase of ISGs in PMN from pregnant cows only on Days 14 and 18 may be explained by the fact that the embryo did not start to elongate before Day 10, and, consequently, there is not enough amount of IFNT leaving the uterus at this time [ 60 ]. IFNT was found to modulate IFNAR2 subunit [ 23 ], and our in vivo data demonstrate upregulated IFNAR2 but not IFNAR1 in PMN from cows in comfort.…”

Section: Discussionmentioning

confidence: 99%

Heat stress modulates polymorphonuclear cell response in early pregnancy cows: I. interferon pathway and oxidative stress

et al. 2021

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One of the major causes of early pregnancy loss is heat stress. In ruminants, interferon tau (IFNT) is the embryo signal to the mother. Once the interferon signaling pathway is activated, it drives gene expression for interferon-stimulated genes (ISGs) and alters neutrophils responses. The aim of the present study was to evaluate interferon (IFN) pathway, ISGs and gene expression in polymorphonuclear leukocytes (PMN) and oxidative stress in dairy cows under heat stress. Pregnant cows had their estrous cycle synchronized and randomly assigned to a comfort or heat stress group. Blood samples were collected at artificial insemination (AI) and on Days 10, 14 and 18 following AI. Pregnant cows were pregnancy checked by ultrasound on Day 30 and confirmed on Day 60 post-AI. Results are presented as mean ± SEM. The corpus luteum (CL) diameter was not different between groups of pregnant cows; concentration of progesterone of pregnant cows on Day 18 following AI was greater in comfort group compared to heat stressed group. Comfort pregnant cows had higher expression of all analyzed genes from interferon pathway, except for IFNAR1, on both Days 14 and 18. Conversely, heat stressed cows did not show altered expression of IFNT pathway genes and ISGs between Days 10, 14, and 18 after AI. The oxidative stress, determined as malondialdehyde (MDA) levels, was greater in heat stress group on Days 10, 14 and 18, independent of pregnancy status. Heat stress negatively influences expression of ISGs, IFN pathway gene expression in neutrophils, and oxidative stress. Our data suggest that lower conception rates in cows under heat stress are multifactorial, with the association of interferon pathway activation and the unbalanced oxidative stress being main contributing factors.

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Section: Discussionmentioning

confidence: 99%

Heat stress modulates polymorphonuclear cell response in early pregnancy cows: I. interferon pathway and oxidative stress

et al. 2021

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“…Progesterone (P4) from the corpus luteum (CL) is critical for the establishment and maintenance of pregnancy and plays a major role in regulating endometrial secretions essential for stimulating and mediating changes in conceptus growth and differentiation throughout early pregnancy in ruminants [27]. Numerous studies have demonstrated an association between elevated P4 and acceleration in conceptus elongation [28,29].…”

Section: Pattern Of Progesterone Concentration For Pregnant Lactatingmentioning

confidence: 99%

Early and Late Embryonic Loss of Smallholder Synchronized Dairy Cows Within Ethiopia

Worku¹,

Tadesse²,

Tegegne³

2020

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This study was carried out on 53 cows selected from smallholder dairy farmers in the Ejerie, Adea Berga and Metarobi western Shoa of Oromia in Ethiopia. All of the cows were investigated in October and November, 2015 for their cyclicity, pregnancy and mainly for early embryonic mortality determination. Milk samples were collected from the 53 of synchronized lactating cows involved in the estrus synchronization programme at the time of AI (day 0). Out of lactating cows, 33 exhibited true heat but due heat detection error, only 26 lactating cows were inseminated in day AI (Artificial Insemination). After it was confirmed that 20 lactating cows were pregnant, then they were continued for further progesterone profiling starting from day 18 to 45 day of post AI at interval of 3 days for determination of early embryonic loss based on progesterone concentration. The milk sample was analyzed by Hormonost Farmer Test. Results of the study indicated that about 60% of lactating cows maintain pregnancy until 45-day post AI whereas 15%, 15% and 10% of early pregnant lactating cow's loss their embryo at 21 st to 24 th days, 27 th to 30 th days and 33 rd day of post AI, respectively. The average progesterone concentration for pregnant cows was 24.46 ng/ml at day 21 to day 45 post AI. Based on finding of this result monitoring and evaluating reproductive traits with progesterone profiling is recommended to improve the fertility of dairy cattle. Finally, embryonic loss detection may serve as a basis for improvement of fertility of dairy cows mean while it will help for designing appropriate breeding management of dairy cattle.

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“…It is produced in increasing quantities [51] [52] [53], if all is going well, by the rapidly dividing fertilized egg. The presence of βhCG enables maintenance of the corpus luteum ensuring that it will continue sufficient production of progesterone needed for implantation and maintenance especially throughout the first trimester.…”

Section: Introductionmentioning

confidence: 99%

HCG Found in WHO Tetanus Vaccine in Kenya Raises Concern in the Developing World

Oller¹,

Shaw²,

Tomljenovic³

et al. 2017

OALib

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In 1993, WHO announced a "birth-control vaccine" for "family planning". Published research shows that by 1976 WHO researchers had conjugated tetanus toxoid (TT) with human chorionic gonadotropin (hCG) producing a "birth-control" vaccine. Conjugating TT with hCG causes pregnancy hormones to be attacked by the immune system. Expected results are abortions in females already pregnant and/or infertility in recipients not yet impregnated. Repeated inoculations prolong infertility. Currently WHO researchers are working on more potent anti-fertility vaccines using recombinant DNA. WHO publications show a long-range purpose to reduce population growth in unstable "less developed countries".

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Progesterone and conceptus-derived factors important for conceptus survival and growth

Cited by 9 publications

References 102 publications

Heat stress modulates polymorphonuclear cell response in early pregnancy cows: I. interferon pathway and oxidative stress

Heat stress modulates polymorphonuclear cell response in early pregnancy cows: I. interferon pathway and oxidative stress

Early and Late Embryonic Loss of Smallholder Synchronized Dairy Cows Within Ethiopia

HCG Found in WHO Tetanus Vaccine in Kenya Raises Concern in the Developing World

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