title: A novel, simple and inexpensive procedure for the simultaneous determination of iopamidol and p-aminohippuric acid for renal function assessment from plasma samples in awake rats.
abstract: The purpose of the current study was to design, validate and implement a novel analytical method for the simultaneous plasma measurement of iopamidol and p-aminohippuric acid (PAH) to estimate renal function in awake rats. A reverse-phase high performance liquid chromatographic (RP-HPLC) method for the simultaneous measurement of iopamidol (for glomerular filtration rate estimation, GFR) and PAH (for tubular secretion determination, TS) was designed and validated using a C-18 column, 0.1M acetic acid-10% acetonitrile (90:10, v/v) as mobile phase, at a flow rate of 0.3 ml/min, and UV detection at 270 nm. Iopamidol (244.8 mg/kg) was administered intravenously followed immediately by sodium PAH (100 mg/kg) to healthy female Sprague-Dawley rats. Plasma samples obtained at 2.5, 5, 10, 15, 20, 30, 45, 60, 90, and 120 min after drug administration were deproteinized with 2.5% trichloroacetic acid containing p-aminobenzoic acid as internal standard, and separated by the validated RP-HPLC method described above. The iopamidol and PAH chromatographic data were analyzed using a non-compartmental model. The results demonstrated that the RP-HPLC method was linear in ranges between 15-120 μg/ml and 2.5-120 μg/ml for iopamidol and PAH, respectively. Precision and accuracy were within 15% for both drugs. Recovery of iopamidol and PAH was 92% and 100%, respectively. Plasma iopamidol and PAH clearances in awake rats, estimates for GFR and TS, respectively, were 1.49±0.20 ml/min and 3.73±0.38 ml/min. In conclusion, the method here described is a simple and reliable procedure, for the simultaneous and time-saving determination of GFR and TS from plasma samples in the conscious rat.
authors.affiliation: Proyecto Camina A.C., Calz. Tlalpan 4430, 14050 Mexico City, Mexico; Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional 2508, 07360 Mexico City, Mexico.
authors.forename: Violeta
authors.initials: V
authors.lastname: Rodríguez-Romero
authors.affiliation: Proyecto Camina A.C., Calz. Tlalpan 4430, 14050 Mexico City, Mexico; Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de Mexico, Av. Guelatao 66, 09230 Mexico City, Mexico.
authors.forename: Karla I
authors.initials: KI
authors.lastname: González-Villalva
authors.affiliation: Departamento de Fisiología Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional 2508, 07360 Mexico City, Mexico.
authors.forename: José L
authors.initials: JL
authors.lastname: Reyes
authors.affiliation: Proyecto Camina A.C., Calz. Tlalpan 4430, 14050 Mexico City, Mexico; Servicio de Bioquímica, Instituto Nacional de Rehabilitación, Calz. Mexico Xochimilco 289, 14389 Mexico City, Mexico.
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Franco-Bourland
authors.affiliation: Proyecto Camina A.C., Calz. Tlalpan 4430, 14050 Mexico City, Mexico; Unidad de Investigación en Enfermedades Neurológicas, Instituto Mexicano del Seguro Social, Av. Cuauhtémoc 330, 06720 Mexico City, Mexico.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Guízar-Sahagún
authors.affiliation: Proyecto Camina A.C., Calz. Tlalpan 4430, 14050 Mexico City, Mexico; Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional 2508, 07360 Mexico City, Mexico.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Castañeda-Hernández
authors.affiliation: Proyecto Camina A.C., Calz. Tlalpan 4430, 14050 Mexico City, Mexico; Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de Mexico, Av. Guelatao 66, 09230 Mexico City, Mexico. Electronic address: letycruza@yahoo.com.mx.
authors.forename: Leticia
authors.initials: L
authors.lastname: Cruz-Antonio
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005260:Female; D007479:Iopamidol / Q000737:chemistry*; D007668:Kidney / Q000502:physiology*; D007677:Kidney Function Tests / Q000379:methods; D010949:Plasma / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D014851:Wakefulness; D010130:p-Aminohippuric Acid / Q000737:chemistry*
chemical_list: D007479:Iopamidol; D010130:p-Aminohippuric Acid
keywords: Analytical method; Glomerular filtration rate; High performance liquid chromatographic; Renal dysfunction; Tubular secretion