Tight junction opening after 36h milk accumulation was associated to a change in mammary secretory tissue activity and dynamics in lactating dairy goats

Abstract : Tight junction opening after 36h milk accumulation was associated to a change in mammary secretory tissue activity and dynamics in lactating dairy goats. H. Ben Chedly1,2, P. Lacasse3, P-G Marnet1,2, S. Wiart-Letort1,2, L. Finot1,2, S. Marion1,2, M. Boutinaud1,2. 1 INRA, UMR1080 Dairy Production, F-35000 Rennes, France, 2 Agrocampus Ouest, UMR1080 Dairy Production, F-35000 Rennes, France, 3 Dairy and Swine R&D Centre, Agriculture and Agri-Food Canada, P.O. Box 90 STN Lennoxville, Sherbrooke, QC, Canada J1M 1Z3. Milk stasis in the mammary gland induces a decrease in milk secretion associated to an opening of tight junctions in mammary tissue. The aim was to study cellular regulations implied in milk synthesis decrease during milk stasis. Eight Alpines goats were submitted to unilateral different milking intervals. The right half udders were milked after 36h while the left udders were milked each 12h. Mammary biopsies were performed after 36h for both half udders. The 36h milk accumulation induced a decrease in milk yield (P<0.001) compared to 12h milk accumulation. This was associated to an opening of tight junction suggested by the tendency to the increase of milk Na/K ratio (P=0.06) in 36h milked udders and by an increase in the blood lactose concentration (P=0.01). An increase in the number of apoptotic cells (P=0.01) associated to an increase in the mRNA levels of pro-apoptotic proteins caspase-3 (P<0.001), Bax (P=0.001) and CLPN2 (P=0.001) were observed in 36h milked udders. Synthetic activity was also affected by milk accumulation since we observed a decrease in kappa-CN and a-lactalbumin mRNA levels (respectively P<0.001 and P=0.02) in 36h milked udders without any significant change in galactosyl-transferase mRNA levels. The 36h milk accumulation induced an increase in mRNA levels of tight junction proteins E-Cadherin (P=0.004) and occludin (P=0.06). This suggest a transcriptional regulatory adaptation of mammary gland to tight junction opening induced by milk stasis. The milk yield decrease observed after 36h milk stasis seems to involve modifications of secretory cell number and activity.
Type de document :
Communication dans un congrès
6th International Symposium for Young Scientist (ISYS)"Human and Animal Development: regulatory mechanisms", Sep 2008, Lublin (POL), Poland. Polish Physiological Society, 59, 14 p., 2008
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Contributeur : Céline Martel <>
Soumis le : vendredi 7 septembre 2012 - 15:59:34
Dernière modification le : mercredi 21 mars 2018 - 16:08:10

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  • HAL Id : hal-00729820, version 1

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H. Ben Chedly, P. Lacasse, Pierre-Guy Marnet, S. Wiart-Letort, L. Finot, et al.. Tight junction opening after 36h milk accumulation was associated to a change in mammary secretory tissue activity and dynamics in lactating dairy goats. 6th International Symposium for Young Scientist (ISYS)"Human and Animal Development: regulatory mechanisms", Sep 2008, Lublin (POL), Poland. Polish Physiological Society, 59, 14 p., 2008. 〈hal-00729820〉

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