Abstract
The immunosuppressive effects of several polyamines were compared. The triamines (norspermidine (NSPD) and spermidine (SPD)) and the tetramines (norspermine (NSPM) and spermine (SPM)) but not the diamines (1,3-diaminopropane and putrescine) inhibited IgM production from murine splenocytes stimulated with LPS. The estimated IC 50 of NSPD was 2.29 × 10 −7 M. The inhibitory effect of NSPD on IgM production was associated with the inhibition of cell growth, because DNA and RNA syntheses measured by 3H-TdR and 3H-UR incorporation were also similarly reduced. Interestingly, the inhibitory effects of NSPD were over ten times greater than those of SPD in spite of the fact that their difference in chemical structure is only one carbon chain. In a FCS-free medium NSPD retained its suppressive activities on LPS-induced IgM production, but the other polyamines were remarkably weakened in their activities. These immunosuppressive effects of NSPD were prevented by adding substances of the intracellular polyamine metabolism, putrescine, SPD or SPM. These findings suggest that NSPD inhibits B cell growth and differentiation by interfering with the polyamine metabolism 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 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.
