Mammary epithelium disruption and mammary epithelial cell exfoliation during milking in dairy cows
| Autor: | H. Quesnel, Lucile Hervé, Rupert M. Bruckmaier, Jacques Portanguen, Vanessa Lollivier, Marion Boutinaud |
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| Přispěvatelé: | Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Elevage [Rennes] (PEGASE), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Veterinary Physiology, Vetsuisse Faculty, Universität Bern [Bern], RUMINFLAME, AGROCAMPUS OUEST-Institut National de la Recherche Agronomique (INRA), AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de la Recherche Agronomique (INRA) |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Hydrocortisone cortisol plasmatique tight junction chemistry.chemical_compound fluids and secretions milking mammary epithelial cell exfoliation ocytocine dairy cows Lactose traite 2. Zero hunger [SDV.BA]Life Sciences [q-bio]/Animal biology food and beverages 04 agricultural and veterinary sciences Dairying Milk medicine.anatomical_structure Mammary Epithelium vache laitière Female medicine.drug medicine.medical_specialty prolactin hormone Biology Milking 03 medical and health sciences Mammary Glands Animal Internal medicine oxytocin Genetics medicine Animals Lactation cellule épithéliale mammaire Cell Proliferation dairy cow 0402 animal and dairy science 040201 dairy & animal science Hormones Epithelium Prolactin 030104 developmental biology Endocrinology Oxytocin chemistry Cattle Animal Science and Zoology jonction serrée Somatic cell count Food Science Hormone prolactine |
| Zdroj: | Journal of Dairy Science Journal of Dairy Science, American Dairy Science Association, 2017, 100 (12), pp.9824-9834. ⟨10.3168/jds.2017-13166⟩ |
| ISSN: | 0022-0302 |
| Popis: | The presence of mammary epithelial cells (MEC) in the milk of ruminants indicates that some MEC are shed from the mammary epithelium; however, the mechanisms that regulate the MEC exfoliation process are not known. Through the release of oxytocin, prolactin, and cortisol and through oxytocin-induced mechanical forces on the mammary epithelium, milking could participate in regulating the MEC exfoliation process. The aims of the present study were to determine the rate of MEC exfoliation throughout milking and to investigate its relationship to mammary epithelium integrity and milking-induced hormone release. Milk samples from 9 Holstein dairy cows producing 40.6 ± 1.36 kg of milk/d were collected at the beginning (after 1 and 2 min), in the middle, and at the end of milking. Milk MEC were purified using an immunomagnetic method. Blood samples were collected before, during, and after milking, and the oxytocin, prolactin, and cortisol concentrations in the samples were measured. Tight junction opening was assessed by plasma lactose concentration and the Na + :K + ratio in milk. The somatic cell count in milk varied during the course of milking; it decreased at the beginning of milking and then increased, reaching the highest values at the end of milking. Exfoliated MEC were present in all milk samples collected. The presence of MEC in the milk sample collected during min 1 of milking, likely corresponding to the cisternal milk fraction, suggests that MEC were exfoliated between milkings. The observed increase in the Na + :K + ratio in milk and in the plasma concentration of lactose indicated that disruption of mammary epithelium integrity occurred during milking. The MEC exfoliation rate at milking was not correlated with the variables describing milking-induced prolactin release but was negatively correlated with cortisol release, suggesting that cortisol may play a role in limiting exfoliation. In conclusion, milking induced a disruption of the mammary epithelial barrier. Mammary epithelial cells may be continuously exfoliated between milkings or exfoliated during milking as a consequence of the oxytocin-induced mechanical forces and the disruption of mammary epithelium integrity. |
| Databáze: | OpenAIRE |
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