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The accumulation of α‐Tocopherol and Retinol in the milk of water buffalo is correlated with the plasma levels of triiodothyronine
Author(s) -
Spagnuolo M. S.,
Cigliano L.,
Sarubbi F.,
Polimeno F.,
Ferrara L.,
Bertoni G.,
Abrescia P.
Publication year - 2003
Publication title -
biofactors
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.204
H-Index - 94
eISSN - 1872-8081
pISSN - 0951-6433
DOI - 10.1002/biof.5520190313
Subject(s) - triiodothyronine , retinol , chemistry , tocopherol , endocrinology , alpha tocopherol , medicine , hormone , biochemistry , vitamin e , biology , vitamin , antioxidant
Milk is the most important source of Retinol and α‐Tocopherol for calves. These antioxidants save the food quality and prevent lipid oxidation in the mammary gland and the calf growing tissues. In Bubalus bubalis , seasonal changes for the plasma levels of both antioxidants were not found. The levels of Retinol and α‐Tocopherol in the milk were 2 and 1.7 times higher in winter than in summer, respectively. These levels were correlated with the plasma level of triiodothyronine, and markedly increased in cows injected with triiodothyronine in summer. The cytosol from alveolar epithelial cells of mammary glands was incubated with α‐Tocopherol and 3 H‐Retinol and, after gel filtration chromatography, both antioxidants were found associated with proteins migrating as a single peak of 33 kD. The amount of α‐Tocopherol and Retinol binding proteins was 1.5 and 2.3 times higher in winter than in summer respectively. The Retinol binding proteins migrated as two bands (33 and 16 kD) by electrophoresis in denaturing and reducing conditions. Our data suggest that triiodothyronine enhances the transport of both liposoluble antioxidants through the blood‐mammary barrier, and demonstrate that proteins of the mammary epithelial cells are involved in such a transport.