Abstract
Amphiphilic peptides with positive charges such as substance P (SP) and mastoparan (MP) are known to induce exocytosis in rat peritoneal mast cells. To elucidate whether and how intracellular Ca 2+ signaling is involved in the peptide-induced exocytosis, here we investigated the relationships between an increase in intracellular free Ca 2+ concentration ([Ca 2+] i) and exocytosis caused by SP and MP. SP and MP induced exocytosis coinciding with an initial rapid and transient [Ca 2+] i increase, but not with a sustained increase. These stimulations were abolished by pertussis toxin, indicating the involvement of the G i-family of G proteins in the peptide signaling. Moreover, the [Ca 2+] i increase was shown to accelerate and potentiate exocytosis, suggesting that the transient increase in [Ca 2+] i positively modified exocytotic secretion. However, it was indicated that the signal of [Ca 2+] i increase was not sufficient for the peptide-induced exocytosis, suggesting the participation of alternative mechanisms other than Ca 2+ signaling in the pathway.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Biochemical and Biophysical Research Communications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
