title: Plasma protein binding of ritodrine at parturition and in nonpregnant women.
abstract: The binding of ritodrine HCl in whole plasma from healthy nonpregnant women, parturients and matched umbilical venous plasma and in solutions of HSA and alpha 1-AGP has been studied by equilibrium dialysis. Binding to plasma from nonpregnant subjects and HSA was independent of ritodrine concentration over a wide range. The free fraction in plasma was high and significantly different between groups of nonpregnant (alpha = 0.64), parturient (alpha = 0.68) and matched umbilical venous plasma (alpha = 0.75). It would seem that variability in transplacental transfer of ritodrine, as a result of plasma binding fluctuations, will be minor.
mesh_terms: D000293:Adolescent; D000328:Adult; D001798:Blood Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D007743:Labor, Obstetric; D008077:Lipoproteins, LDL / Q000032:analysis; D008431:Maternal-Fetal Exchange; D008875:Middle Aged; D009961:Orosomucoid / Q000032:analysis; D011247:Pregnancy; D011412:Propanolamines / Q000378:metabolism*; D012312:Ritodrine / Q000378:metabolism*; D012709:Serum Albumin / Q000032:analysis
chemical_list: D001798:Blood Proteins; D008077:Lipoproteins, LDL; D009961:Orosomucoid; D011412:Propanolamines; D012709:Serum Albumin; D012312:Ritodrine