title: Low expression of the antibacterial factor L-amino acid oxidase in bovine mammary gland.
abstract: In the mouse, L-amino acid oxidase (LAO) produces hydrogen peroxide by utilizing free amino acids and is a proven antibacterial factor in mammary glands. Mastitis, a bacterial infection of the mammary gland, is the most frequent disease in dairy cattle. Here, we investigate whether LAO is expressed in the mammary gland of dairy cattle and is antibacterial. In dairy cattle, the expression level of LAO mRNA in the mammary gland was considerably lower than that in mice, and LAO activity was not observed in cattle milk that produced hydrogen peroxide. The expression of LAO mRNA was also low in Japanese Black cattle, the same as in Holstein cattle. A higher LAO mRNA expression was observed in the mastitis glands than in the lactating glands. Furthermore, spleen and lymph nodes expressed high levels of LAO mRNA in dairy cattle. We conclude that mammary glands in dairy cattle have lower ability to express the LAO gene compared to that in mice, which may result in a high incidence of mastitis.
authors: Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Tokyo University of Agriculture and Technology, Fuchu, Japan.
authors: Kentaro
authors: K
authors: Nagaoka
authors: Haolin
authors: H
authors: Zhang
authors: Masahiro
authors: M
authors: Arakuni
authors: Kazuyoshi
authors: K
authors: Taya
authors: Gen
authors: G
authors: Watanabe
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D000900:Anti-Bacterial Agents; D002417:Cattle; D005260:Female; D015870:Gene Expression; D006861:Hydrogen Peroxide / Q000378:metabolism; D050830:L-Amino Acid Oxidase / Q000235:genetics* / Q000502:physiology; D007774:Lactation / Q000235:genetics / Q000378:metabolism; D008321:Mammary Glands, Animal / Q000201:enzymology*; D008414:Mastitis, Bovine / Q000201:enzymology* / Q000235:genetics*; D051379:Mice; D008813:Mice, Inbred ICR; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D000596:Amino Acids; D000900:Anti-Bacterial Agents; D012333:RNA, Messenger; D006861:Hydrogen Peroxide; D050830:L-Amino Acid Oxidase
keywords: amino acid; hydrogen peroxide; innate immune system; mastitis