Saporin Clearance

Q: I am planning an experiment to investigate the effects of ablation of spinal NK-1r-expressing cells (using intrathecal injection of SSP-SAP, Cat. #IT-11). In the first part of the experiment I want to destroy the NK-1r-expressing cells before surgical modification. I am unsure how long after injection of SSP-SAP I should carry out the surgery. I was thinking of carrying out surgery at the two-week time point as in a 2007 Neuroscience paper by Wiley et al. Their immunocytochemistry showed a large reduction in staining at this time point. Any advice you could give me would be much appreciated.

A: Two weeks is probably fine. Generally cells begin to lose function at four days, but people wait longer because there is a clean-up by microglia/macrophage that removes the markers that people use for detection/demonstration of efficacy. Mantyh et al. were conservative with a 30-day wait for saporin clearance.

Related: SSP-SAP (Cat. #IT-11)

References

  1. Wiley RG et al. Anti-nociceptive effects of selectively destroying substance P receptor-expressing dorsal horn neurons using [Sar(9),Met(O(2))(11)]-substance P-saporin: Behavioral and anatomical analyses. Neuroscience 146:1333-1345, 2007.
  2. Mantyh PW et al. Inhibition of hyperalgesia by ablation of lamina I spinal neurons expressing the substance P receptor. Science 278:275-279, 1997.