Implication of Protein Kinase C and Calcium-Calmodulin System in the Regulatory Mechanism of Endothelial Prostacyclin Generation
Year: 1988
Type: article
Abstract: The role of protein kinase C pathway and Ca++-calmodulin system in prostacyclin (PGI2) generation in cultured human vascular endothelial cells (VEC) was investigated. VEC were isolated and cultured from human umbilical cord veins. PGI2 released from VEC was assayed by RIA. Cytosolic free Ca++ concentration ([Ca++]i) was measured using fura-2/AM. Results were as follows: The basal level of [Ca++]i in VEC was lower (7.27±1.41×10-9M) than those of other cells. Released Ca++ from storage sites was considered to be essential for the maintenance of basal PGI2 generation. From the experimental results, the initial increase of [Ca++]i was necessary and the basal PGI2 generation was also maintained in the Ca++-free solution. The addition of Ca++ ionophore A23187 (A23187) or bradykinin (BK) increased [Ca++]i and PGI2 generation. The increase of [Ca++]i induced by A23187 was sequential while the increase induced by BK was transient. The pretreatment of the cells with a calmodulin inhibitor W-7 (10-5M, 10min) or a protein kinase C inhibitor H-7 (10-5M, 30min) suppressed the enhancement of [Ca++]i and PGI2 generation induced by A23187. Although pretreatment abolished these increased parameters induced by BK. Through these results it was concluded that protein kinase C pathway and Ca++-calmodulin systems contributed partially to increased [Ca++]i and PGI2 generation induced by A23187 or BK.
Institution: Kyoto Prefectural University of Medicine
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W601424352