{"id":2851,"date":"2024-03-24T16:50:17","date_gmt":"2024-03-24T15:50:17","guid":{"rendered":"https:\/\/www.rumexperts.vet\/?post_type=training&#038;p=2851"},"modified":"2024-03-24T16:50:17","modified_gmt":"2024-03-24T15:50:17","slug":"progesterone-interferon-et-pag-un-menage-a-trois","status":"publish","type":"training","link":"https:\/\/www.rumexperts.vet\/en\/training\/progesterone-interferon-et-pag-un-menage-a-trois","title":{"rendered":"Progest\u00e9rone, interf\u00e9ron et PAG : un m\u00e9nage \u00e0 trois"},"content":{"rendered":"<div class=\"fusion-fullwidth fullwidth-box fusion-builder-row-1 fusion-flex-container has-pattern-background has-mask-background nonhundred-percent-fullwidth non-hundred-percent-height-scrolling\" style=\"--awb-border-radius-top-left:0px;--awb-border-radius-top-right:0px;--awb-border-radius-bottom-right:0px;--awb-border-radius-bottom-left:0px;--awb-flex-wrap:wrap;\" ><div class=\"fusion-builder-row fusion-row fusion-flex-align-items-flex-start fusion-flex-content-wrap\" style=\"max-width:1248px;margin-left: calc(-4% \/ 2 );margin-right: calc(-4% \/ 2 );\"><div class=\"fusion-layout-column fusion_builder_column fusion-builder-column-0 fusion_builder_column_1_1 1_1 fusion-flex-column\" style=\"--awb-bg-size:cover;--awb-width-large:100%;--awb-margin-top-large:0px;--awb-spacing-right-large:1.92%;--awb-margin-bottom-large:20px;--awb-spacing-left-large:1.92%;--awb-width-medium:100%;--awb-order-medium:0;--awb-spacing-right-medium:1.92%;--awb-spacing-left-medium:1.92%;--awb-width-small:100%;--awb-order-small:0;--awb-spacing-right-small:1.92%;--awb-spacing-left-small:1.92%;\"><div class=\"fusion-column-wrapper fusion-column-has-shadow fusion-flex-justify-content-flex-start fusion-content-layout-column\"><div class=\"fusion-text fusion-text-1\"><p>REFERENCES\u00a0: Santos et al. Time to increase in pregnancy-specific protein B following artificial insemination is a direct determinant of subsequent pregnancy loss in lactating dairy cows. J. Dairy Sci. 106:3734\u20133747 <a href=\"https:\/\/doi.org\/10.3168\/jds.2022-22553\">https:\/\/doi.org\/10.3168\/jds.2022-22553<\/a> et Domingues RR et al. Is pregnancy loss initiated by embryonic death or luteal regression? Profiles of pregnancy-associated glycoproteins during elevated progesterone and pregnancy loss. JDS Communications, 2023; 4:149\u201315. <a href=\"https:\/\/doi.org\/10.3168\/jdsc.2022-0282\">https:\/\/doi.org\/10.3168\/jdsc.2022-0282<\/a><\/p>\n<p>UN BREF RAPPEL<\/p>\n<p>Au cours des trois premi\u00e8res semaines de son d\u00e9veloppement, l\u2019embryon conna\u00eet d\u2019importantes <u>modifications morphologiques<\/u>. Une fois sorti de sa pellucide (phase de hatching), le blastocyste devient plus ovo\u00efde. Il s\u2019allonge progressivement et devient tubulaire puis filamenteux. Au bout d\u2019une vingtaine de jours, les premiers contacts avec l\u2019endom\u00e8tre s\u2019\u00e9tablissent. Y apparaissent des cellules bi ou multinucl\u00e9es (Figure).<\/p>\n<p>Ces modifications morphologiques s\u2019accompagnent de <u>modifications hormonales<\/u>.<\/p>\n<ul>\n<li>On le sait, plus pr\u00e9coce et plus importante est la synth\u00e8se de PROGESTERONE par le corps jaune faisant suite \u00e0 l\u2019ovulation et moindre sera le risque de mortalit\u00e9 embryonnaire tr\u00e8s pr\u00e9coce (1<sup>\u00e8re<\/sup> semaine suivant la f\u00e9condation). Cette progest\u00e9rone contribue largement \u00e0 l\u2019\u00e9longation de l\u2019embryon.<\/li>\n<li>L\u2019\u00e9longation de l\u2019embryon s\u2019accompagne de la synth\u00e8se de l\u2019INTERFERON TAU. Cette hormone va inhiber les r\u00e9cepteurs endom\u00e9triaux \u00e0 l\u2019ocytocine et donc inhiber la lut\u00e9olyse\u00a0: la gestation se maintient.<\/li>\n<li>L\u2019apparition de cellules bi ou multinucl\u00e9es dans l\u2019endom\u00e8tre, signe des premiers attachements de la v\u00e9sicule embryonnaire \u00e0 l\u2019ut\u00e9rus et donc du d\u00e9veloppement placentaire, se traduit par la synth\u00e8se de la PAG (Pregnancy Associated Glycoprot\u00e9in).<\/li>\n<\/ul>\n<p>NATURE DES RELATIONS ENTRE DEVELOPPEMENT EMBRYONNARE ET LES HORMONES<\/p>\n<p>Les deux \u00e9tudes r\u00e9f\u00e9renc\u00e9es avaient poud but d\u2019analyser les effets de la progest\u00e9ron\u00e9mie sur les concentrations de la PAG et le risque de mortalit\u00e9 embryonnaire.\u00a0 Elles ont pour ce faire eu recours \u00e0 des injections d\u2019hCG (3000 et 3300 UI) r\u00e9alis\u00e9es aux jours 2 \u00e0 5 ou 7 \u00e0 13 jours apr\u00e8s l\u2019ins\u00e9mination.<\/p>\n<p>L\u2019injection d\u2019hCG induit une augmentation de la progest\u00e9ron\u00e9mie par un effet direct sur le corps jaune existant et\/ou par l\u2019induction d\u2019un corps jaune accessoire (sur l\u2019ovaire ipsi ou contralat\u00e9ral au corps jaune principal) r\u00e9sultant de la lut\u00e9inisation (pr\u00e9c\u00e9d\u00e9e ou non de l\u2019ovulation) du follicule dominant pr\u00e9sent lors de l\u2019injection.<\/p>\n<p>L\u2019injection d\u2019hCG n\u2019a pas eu d\u2019effet sur le risque de mortalit\u00e9 embryonnaire entre les jours 17 et 33. Ce traitement et donc la concentration en progest\u00e9rone n\u2019a pas eu d\u2019effet sur le moment d\u2019apparition chez les vaches gestantes d\u2019une augmentation significative de la PAG (10 %) \u00e0 savoir le 21<sup>\u00e8me<\/sup> jour suivant l\u2019ovulation, jour qui par ailleurs correspond au moment ou la concentration en PAG \u00e9tait significativement diff\u00e9rente entre les vaches gestantes et non gestantes. Plus tard cette augmentation appara\u00eet et plus grand est le risque de ME. Selon Santos (2023), l\u2019apparition de cette augmentation au-del\u00e0 du 21<sup>\u00e8me<\/sup> jour suivant l\u2019ovulation, multiplie par 4 le risque de ME. Ce d\u00e9lai serait plus \u00e9lev\u00e9 chez les multipares (21,07 J) que chez les primipares (20,48 J).<\/p>\n<p>Le suivi de la progest\u00e9rone et de la PAG ont permis de d\u00e9terminer que dans 53 % des cas de mortalit\u00e9 embryonnaire observ\u00e9s entre le 21<sup>\u00e8me<\/sup> et le 33<sup>\u00e8me<\/sup> jour de gestation, une lut\u00e9olyse (27,7 jours en moyenne) a pr\u00e9c\u00e9d\u00e9 la diminution de la PAG, l\u2019inverse ayant \u00e9t\u00e9 observ\u00e9 dans 47 % des cas, la diminution de la PAG \u00e9tant apparue 29,3 jours en moyenne. Il est int\u00e9ressant d\u2019observer que la PAG se maintient durant les 3 jours suivant la lut\u00e9olyse. A l\u2019inverse, une diminution de la PAG ne s\u2019accompagne pas d\u2019une lut\u00e9olyse.<\/p>\n<\/div><div class=\"fusion-image-element \" style=\"--awb-caption-title-font-family:var(--h2_typography-font-family);--awb-caption-title-font-weight:var(--h2_typography-font-weight);--awb-caption-title-font-style:var(--h2_typography-font-style);--awb-caption-title-size:var(--h2_typography-font-size);--awb-caption-title-transform:var(--h2_typography-text-transform);--awb-caption-title-line-height:var(--h2_typography-line-height);--awb-caption-title-letter-spacing:var(--h2_typography-letter-spacing);\"><span class=\" fusion-imageframe imageframe-none imageframe-1 hover-type-none\"><img decoding=\"async\" width=\"1900\" height=\"1062\" title=\"Turenne steps of embryo development\" src=\"https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2024\/03\/Turenne-steps-of-embryo-development-scaled.jpg\" data-orig-src=\"https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2024\/03\/Turenne-steps-of-embryo-development-scaled.jpg\" alt class=\"lazyload img-responsive wp-image-2853\" srcset=\"data:image\/svg+xml,%3Csvg%20xmlns%3D%27http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%27%20width%3D%271900%27%20height%3D%271062%27%20viewBox%3D%270%200%201900%201062%27%3E%3Crect%20width%3D%271900%27%20height%3D%271062%27%20fill-opacity%3D%220%22%2F%3E%3C%2Fsvg%3E\" data-srcset=\"https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2024\/03\/Turenne-steps-of-embryo-development-200x112.jpg 200w, https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2024\/03\/Turenne-steps-of-embryo-development-400x224.jpg 400w, https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2024\/03\/Turenne-steps-of-embryo-development-600x335.jpg 600w, https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2024\/03\/Turenne-steps-of-embryo-development-800x447.jpg 800w, https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2024\/03\/Turenne-steps-of-embryo-development-1200x671.jpg 1200w, https:\/\/www.rumexperts.vet\/wp-content\/uploads\/2024\/03\/Turenne-steps-of-embryo-development-scaled.jpg 1900w\" data-sizes=\"auto\" data-orig-sizes=\"(max-width: 640px) 100vw, 1200px\" \/><\/span><\/div><\/div><\/div><\/div><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":20,"featured_media":2852,"template":"","keyword":[],"theme":[59],"class_list":["post-2851","training","type-training","status-publish","has-post-thumbnail","hentry","theme-reproduction-en"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/training\/2851","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/training"}],"about":[{"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/types\/training"}],"author":[{"embeddable":true,"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/users\/20"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/media\/2852"}],"wp:attachment":[{"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/media?parent=2851"}],"wp:term":[{"taxonomy":"keyword","embeddable":true,"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/keyword?post=2851"},{"taxonomy":"theme","embeddable":true,"href":"https:\/\/www.rumexperts.vet\/en\/wp-json\/wp\/v2\/theme?post=2851"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}