Abstract
Using front-surface fluorometry with fura-2 and porcine aortic valvular strips, we investigated the effect of motilin, a gastrointestinal peptide, on the cytosolic Ca2+ concentration ([Ca2+]i) of endothelial cells in situ. Motilin induced a biphasic elevation of [Ca2+]i of the endothelial cells on the porcine aortic valvular strips. To investigate the physiological role of these Ca2+ transients in the endothelial cells, we determined the effect of motilin on [Ca2+]i as well as the tension of the smooth muscles in the porcine coronary strips with an intact endothelium. Motilin decreased [Ca2+]i and the tension of the coronary smooth muscle precontracted by U46619, a thromboxane A2 analogue, in an endothelium-dependent manner. In the presence of indomethacin (a cycloxygenase inhibitor), motilin induced an endothelium-dependent relaxation of the coronary strips which was partially inhibited by Nω-nitro-L-arginine (L-NNA; a NO synthase inhibitor). These results thus indicate that motilin induces Ca2+ transients of the endothelial cells while it also induces vasorelaxation, which may be mediated by both L-NNA sensitive and resistant factors that are derived from the endothelium.
Original language | English |
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Pages (from-to) | 346-353 |
Number of pages | 8 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 202 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jul 15 1994 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology