title: Placental transfer and renal clearance of sulphamethoxazole and its metabolite N4-acetylsulphamethoxazole in a pregnant ewe.
abstract: Sulphamethoxazole and its metabolite, N4-acetylsulphamethoxazole, were shown to cross the placenta of a pregnant ewe. The plasma concentration of N4-acetylsulphamethoxazole increased in the foetus due to the limited elimination properties of the immature kidney. The amniotic fluid concentration of sulphamethoxazole and N4-acetylsulphamethoxazole were low, amounting to 2.0 and 0.46 micrograms/ml respectively. Protein binding of the sulphonamides was slightly higher in the foetus than in the ewe.
mesh_terms: D000818:Animals; D005260:Female; D007668:Kidney / Q000378:metabolism; D008431:Maternal-Fetal Exchange; D008657:Metabolic Clearance Rate; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D012756:Sheep / Q000097:blood* / Q000378:metabolism; D013420:Sulfamethoxazole / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism*
chemical_list: C021282:N(4)-acetylsulfamethoxazole; D013420:Sulfamethoxazole