Characterization of the prostaglandin receptors in human osteoblasts in culture

Prostaglandins have complex actions on bone metabolism that depend on inter actions with different types and subtypes of receptors. Our objective was t o characterize the prostaglandins receptors present in primary cultures of human osteoblasts. PT-POP analysis revealed the presence of DP, EP4, IF, FP and TP receptor mRNA in primary cultures of human osteoblasts. FP receptor mRNA was detected only after 3 weeks of confluency, all the others were de tected at every culture time tested. To verify the functionality of these r eceptors we challenged the cells with the prostanoids and synthetic analogu es and determined the intracellular levels of cAMP. All receptors found by RT-PCR were coupled to second messengers except for the DP subtype. These r esults clearly show the presence of functional EP4, IP, FP and TP receptors in human osteoblasts in culture. (C) 2001 Harcourt Publishers Ltd.