Figure 3.

mIIa but not mIIb is down-regulated by PTH. OK cells were transfected with mIIa (A) or mIIb (B) and processed for PTH experiment (see Materials and Methods). Cells were treated with 10⁻⁸ M 1–34 PTH (Upper) or with 10⁻⁶ M 3–34 PTH (Lower) for 2 and 4 h. Down-regulation of mIIa is indicated by the disappearance of its specific “patches.” Results are representative of four independent experiments.