“…To test the regulatory effect of AVP on tight –junction proteins in the ED and ES epithelium, the V2R specific agonist 1-Desamino-8-D-Arginin-Vasopressin (dDAVP; Bachem, Bubendorf, Switzerland) in the range of physiological concentrations of 10 −6 M, 10 −8 M and 10 −10 M and of the V2R antagonist H-9400 (concentrations: 10 −6 M μM, 10 −8 M and 10 −10 M; Bachem, Bubendorf, Switzerland) were added to the DMEM/F12 medium without HEPES supplemented with 25% horse serum, 10 IU/ml penicillin/streptomycin, 2 mM L-glutamine, 0,9 mg/ml sodium bicarbonate (ThermoFisher Scientific)114, respectively. Incubation of ES-specimens was performed for 30 min, 1 h, and 3 h. The range of physiological concentration values115 and time periods were selected from former studies dealing with AVP stimulation experiments in the ES and the kidney100116117.…”