SUN B8155

SUN B8155, a non-peptide agonist of calcitonin (CT) receptor, selectively mimics the biological actions of calcitonin. Calcitonin, a 32-amino acid peptide hormone secreted mainly from the thyroid gland, plays an important role in maintaining bone homeostasis^[1]. In Vitro: SUN B8155 (1-1000 μM; 1 hour) stimulates intracellular cAMP formation in T47D cells in a concentration-dependent manner; the concentration of synthesized cAMP increased by approximately 42-fold at the highest concentration. SUN B8155 also stimulates cAMP formation in the rat osteogenic sarcoma-derived cell line, UMR106-06^[1].
SUN B8155 does not stimulate cAMP formation in CHO/hPTHR or parental CHO cells, but fully stimulates cAMP formation in CHO/hCTR cells in a concentration-dependent manner with an EC₅₀ of 21 μM^[1]. In Vivo: SUN B8155 (100 mg/kg; i.p.) results in a significant reduction of serum calcium concentration by approximately 9% at 30 min after administration. Human CT also reduces serum calcium in a dose-dependent manner at 30 min (0.1 and 0.3 μg/kg) and 60 min (0.3 μg/kg) after administration^[1].