The establishment of ACTHR detecting method and assay of ACTHR on rat thymocytes / 中国免疫学杂志

ABSTRACT

In this paper, it was reported that rat thymocytes harbor both high and low affinity ACTHR. The proper number of thymocytes used for deterting ACTHR varies from 1?10~6 /0.2 ml to 2 ?10~6 /ml, the maximum binding of ACTH to ACTHR occurs at 20 minutes. The IC_(50) for ACTH concentration is 800 nM or so. The saturation curves show that thymocyte ACTHRs are saturated at the concentration of 2.5 nM of ~(125)IACTH. There are high affinity ACTHR of 840 sites/cell on thymocyte (KD=0.15nM, Bmax = 2. 8 fmol/2 ? 10~6 cells); whereas low affinity ACTHRs are 12400 sites/cell (KD=4.2 nM, Bmax = 41.5 fmol/2 ? 10~6 cells).Moreover amputation stress can reduce thymocyte ACTHR remarkably.