Related Experiment Video
Updated: Aug 11, 2026
![Development and Characterization of In Vitro Microvessel Network and Quantitative Measurements of Endothelial [Ca2+]i and Nitric Oxide Production](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F54014.jpg&w=3840&q=50)
Development and Characterization of In Vitro Microvessel Network and Quantitative Measurements of Endothelial [Ca2+]i and Nitric Oxide Production
Published on: May 19, 2016
Involvement of Gi/o in the PAR-4-induced NO production in endothelial cells
Fumi Momota1, Katsuya Hirano, Mayumi Hirano
1Division of Molecular Cardiology, Research Institute of Angiocardiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Abstract:
We investigated the involvement of G(i/o) protein in NO production following the activation of proteinase-activated receptor-4 (PAR-4) in cultured bovine aortic endothelial cells. AYPGKF-NH(2) (PAR-4 activating peptide), thrombin, and ionomycin induced a concentration-dependent NO production, with the maximal production seen at 30 microM, 0.1U/ml, and 1 microM, respectively. Ionomycin elevated [Ca(2+)](i) in a concentration-dependent manner. However, AYPGKF-NH(2) and thrombin induced no [Ca(2+)](i) elevation. The loading of cells with BAPTA almost completely inhibited both the NO production and [Ca(2+)](i) elevation induced by 1 microM ionomycin, while it had no significant effect on the AYPGKF-NH(2)-induced NO production. Treatment with pertussis toxin inhibited the AYPGKF-NH(2)-induced NO production, while it had no effect on the ionomycin-induced NO production. Our findings thus demonstrate, for the first time, that PAR-4 activation induced NO production in a manner mostly independent of the Ca(2+) signal and also that G(i/o) is involved in such NO production in vascular endothelial cells.
More Related Videos
Related Concept Videos
Nitric Oxide Signaling Pathway
Regulation of Angiogenesis and Blood Supply
Mechanism of Angiogenesis
Intracellular Signaling Affects Focal Adhesions
Some...
Activation of Integrins
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.

