Abstract
VIP/helodermin receptors and PGE 1 receptors coupled to adenylate cyclase underwent rapid homologous desensitization and/or down regulation in the human lymphoma SUP-T1 cell line: helodermin- and PGE 1-stimulated abenylate cyclase activities in membranes decreased by 75% and 80%, respectively, after a 16-hr incubation of cells with 30 nM VIP or 0.1 μM PGE 1. The adenylate cyclase response to helodermin doubled within 120 min of incubation with fresh medium, this part of the resensitization process being not significantly reduced by cycloheximide. The second slower phase of recovery attained 80% of control values after 8 hr and was significantly affected by cycloheximide added at time 0. These data were corroborated by our observations on [ 125I]helodermin binding to intact cells. In the case of functional PGE 1 receptors, sixty percent of the adenylate cyclase response reapeared within 30–60 min, with the second phase of recovery leading, after 2–3 hr to 80–85% of control values of PGE 1-stimulated enzyme activity. This resensitization process to PGE 1 was, as a whole, cycloheximide sensitive.
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 callDisclaimer: 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.
