title: The immunologic and antioxidant effects of L-phenylalanine on the uterine implantation of mice embryos during early pregnancy.
abstract: L-phenylalanine (L-PHE) is a synthetic precursor of catecholamines. Because it cannot be synthesised by an organism, it must be absorbed from the environment. Despite the wide use of L-PHE, whether L-PHE has a negative impact on embryo implantation and development is poorly understood. This study attempted to determine the roles of L-PHE in embryo implantation and development and in the immune response and antioxidant status of the uterus in early pregnancy mice injected intraperitoneally with 320 mg/kg L-PHE. The embryo number of treated mice decreased by 57.6%, and the size of their embryos was reduced by 2.8% (P⟩0.05) along the long diameter and 11.9% (P⟨0.05) along the short diameter at E9 compared with control mice. In addition, L-PHE significantly suppressed B lymphocyte proliferation. L-PHE increased IL-2 secretion but decreased the IL-4 concentration, thereby up-regulating the ratio of IL-2/IL-4 to 1.37-8.45. An analysis of the oxidant and antioxidant status showed that, compared with the control mice, the level of superoxide dismutase activity decreased by 21.54-39.94% and the glutathione peroxidase activity decreased by 15.27-18.96% among the L-PHE-treated mice at E1-E9. However, the malonaldehyde content increased by 14.29%-90.11% among the L-PHE-treated mice. Therefore, L-PHE impaired embryo implantation by disrupting cytokine-based immunity and oxidative stress in the uterus.
authors.affiliation: Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Beijing, China.
authors.forename: Yulan
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Beijing, China.
authors.forename: Yongping
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Beijing, China.
authors.forename: Guanhui
authors.initials: G
authors.lastname: Liu
authors.affiliation: Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Beijing, China.
authors.forename: Zixu
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Cao
authors.affiliation: Laboratory of Veterinary Anatomy, College of Animal Medicine, China Agricultural University, Beijing, China. yxchen@cau.edu.cn.
authors.forename: Yaoxing
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Microbiology, Immunology and Pathology, Colorado State University, Ft. Collins, CO, USA.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Yang
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis; D010064:Embryo Implantation / Q000187:drug effects*; D047108:Embryonic Development / Q000187:drug effects; D005260:Female; D008054:Lipid Peroxides / Q000378:metabolism; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology; D051379:Mice; D008813:Mice, Inbred ICR; D010649:Phenylalanine / Q000494:pharmacology*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000187:drug effects*; D014599:Uterus / Q000187:drug effects* / Q000276:immunology*
chemical_list: D000975:Antioxidants; D016207:Cytokines; D008054:Lipid Peroxides; D010649:Phenylalanine