Atrial natriuretic factor receptors and stimulation of cyclic GMP formation in normal and malignant osteoblasts

Abstract

Synthetic rat atrial natriuretic factor (Ile-ANF-26) stimulated cyclic GMP formation by up to several hundred-fold in osteoblast-rich cultures from newborn rat calvaria and in clonal osteogenic sarcoma cells (UMR 106-01) which are phenotypically osteoblast. ANF had no effect on the cyclic AMP response to parathyroid hormone in the same cells. Specific, high-affinity binding sites for ANF were identified in both cell types, with Kd and receptor numbers in normal osteoblasts of 1.2 ± 0.1 × 10-10 M and 42 ± 4 × 103 per cell, and in UMR 106-01 cells of 1.4 ± 0.1 × 10-10M and 22 ± 4 × 103per cell. © 1986.