INTRACELLULAR CA2-CELLS FROM THE NASAL INFERIOR TURBINATE( MOBILIZATION IN CULTURED HUMAN MUCOSAL MICROVASCULAR ENDOTHELIAL)

Human mucosal microvascular endothelial cells (HMMECs) were isolated a nd cultured from the mucosa of nasal inferior turbinates. These cells were identified by human factor-VIII antigen and UEA-I. We also invest igated alterations in intracellular calcium concentration [Ca2+](i), i n HMMECs using the Ca2+-sensitive dye fura-2. Depolarization by high K + (150 mM) induced no changes in [Ca2+](i) in HMMECs, thereby indicati ng the lack of voltage-dependent Ca2+ channels in these cells. Extrace llular ATP increased [Ca2+](i) in HMMECs both in the presence and abse nce of extracellular Ca2+. These results suggest that ATP may induce a release of Ca2+ from intracellular stores in HMMECs. Adenosine induce d no changes in [Ca2+](i) in HMMECs. It is thus likely that HMMECs obt ained from the nasal inferior turbinate may carry P-2-purinoceptors bu t not P-1-purinoceptors.