Pharmacokinetics Study of Recombinant Hirudin in the Plasma of Rats Using Chromogenic Substrate, ELISA, and Radioisotope Assays

Abstract

AimTo compare the analytical methods used to study the pharmacokinetics of recombinant hirudin in the plasma of rats that had been injected with 125I-recombinant hirudin.Methods2.0 mg/kg 125I-recombinant hirudin were injected intravenously into rats. The recombinant hirudins in the plasma was analyzed by chromogenic substrate assay, enzyme-linked immunosorbent assay (ELISA), total radioisotope assay (RA) and trichloroacetic acid pre-treated total radioisotope assay (TCA-RA).ResultsThe chromogenic substrate assay standard curve was linear over the concentration range from 3.12 to 40.00 ng/ml for the recombinant hirudin in plasma. The relative standard deviations (RSD) for the intra- and inter-day variation were 5.0 to 6.3% and 11.9 to 12.6%, respectively. The recoveries of recombinant hirudin was 89.8% to 100.7%. The limit of quantification (LOQ) was 3.12 ng/ml. The concentration-time curve of the recombinant hirudin in the plasma could be explained as a two-compartment model. Pharmacokinetic parameters, including the half-life of distribution phase (t1/2 α), the half-life of elimination phase (t1/2 β), volume of apparent distribution (Vd), and area under the concentration-time curve from zero to infinite time (AUC0–t) were 7.59 min, 46.99 min, 0.17 L/kg, and 204.5 mg/L/min, respectively, as determined by chromogenic substrate assay; 6.41 min, 47.28 min, 1.24 L/kg, and 575.18 mg/L/min, respectively, as determined by ELISA; 3.69 min, 701.90 min, 0.04 L/kg, and 4189 mg/L/min, respectively as determined by RA; and 4.57 min, 724.9 min, 0.09 L/kg, and 2329 mg/L/min, respectively, as determined by TCA-RA.ConclusionsThe chromogenic substrate assay on the concentration dynamics of the recombinant hirudin in the plasma is a specific, sensitive, and accurate analytical method for pharmacokinetic studies. Moreover, the pharmacokinetic parameters determined by the chromogenic substrate assay and ELISA are congruent except for AUC.

A Systematic Study of Dysregulated MicroRNA in Type 2 Diabetes Mellitus

“…The main characteristics extracted from various datasets are summarized in Table 1, which includes the number of patients investigated, the measurement platform, type of sample used and the identity of miRNAs in the study [23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81]. Comparing results from multiple tissues provides an overall view of the impact of miRNAs in T2DM pathology.…”

Bioactive proteins and peptides isolated from Chinese medicines with pharmaceutical potential

“…Bivalirudin was approved by the FDA in December 2000 and was frequently used as an anticoagulant in percutaneous coronary intervention [ 22 , 23 ]. A pharmacokinetic study of recombinant hirudin with chromogenic substrate assay and ELISA demonstrated that its half-life in the plasma in male Sprague Dawley rats was less than 1 h [ 24 ].…”