Exendin 4 enzyme immunoassay kit

Sodium alginate (Mw: approx.180 kDa, pharmaceutical grade) was a gift from Huanghai Biological Pharmaceutical Co. Ltd (Qingdao). Sodium hyaluronate (Mw: 1,955 kDa, pharmaceutical grade) was purchased from Freda Biotechnology Co. Ltd (Shandong). Exenatide was from GL Biochem Ltd (Shanghai). Blood glucose meter and test strips were purchased from Johnson & Johnson Company (USA). Exendin-4 enzyme immunoassay kit (EK-070-94) was purchased from Phoenix Pharmaceuticals Inc. (USA). Bicinchoninic acid (BCA) protein assay kit was purchased from Generay Biotech Co. Ltd (Shanghai). All other chemicals were pharmaceutical grade and commercially available.

Male ICR mice were subcutaneously (s.c.) administered with 1.6 mg/kg of ExA (n = 3). A blood specimen was withdrawn from each mouse at 0, 10 min, 1 h, 3 h, 8 h, 1 day, 2 day, 3 day, 4 day, 7 day, 10 day, and 14 day post-administration. The blood was collected from the venous sinus using a capillary tube, and the plasma sample was acquired by centrifugation of the blood at 1000 rpm for 5 min. The plasma samples were analyzed by using the exendin-4 enzyme immunoassay kit (EK-070-94, Phoenix Pharmaceuticals, Inc., Burlingame, CA, USA), according to the manufacturer’s instruction. Based on the plasma concentration-versus-time profiles of the ExA, the pharmacokinetic profiles of the plasma samples were analyzed by using non-compartmental analysis (NCA) with Phoenix^® WinNonlin^® software (Certara LP. Princeton, NJ, US). The PK parameters such as the half-life (t_1/2), the maximum plasma concentration (C_max), and the time to reach the C_max (T_max) were calculated.