To determine which subtype of nociceptor, peptidergic or non-peptidergic, is involved in the mechanical hyperalgesia induced by LMWH (low molecular weight hyaluronan), rats were pretreated with neurotoxins previously shown to selectively deplete these two types of sensory neurons: Isolectin B4 (IB4)-saporin (SAP), which acts on IB4-positive, non-peptidergic neurons (Cat. #IT-10 IB4-SAP), and substance P-saporin (Cat. #IT-11 SSP-SAP), shown to deplete peptidergic fibers. Both IB4-SAP and SSP-SAP were diluted in saline for nonpetidergic (3.2 μg/rat for IB4-SAP) and peptidergic (100 ng/rat for SSP-SAP) fibers. The toxins were administered intrathecally, in a volume of 20 μl, 14 days before the intradermal injection of LMWH on the dorsum of the hind paw.
CD44 Signaling Mediates High Molecular Weight Hyaluronan-Induced Anti-Hyperalgesia. Ferrari, LF, Khomula, EV, Araldi, D, & Levine, JD. (2017). DOI: 10.1523/J Neurosci 2695-17. PMID: 29175954
IB4-SAP (Cat. #IT-10) is a tool for eliminating cells that express α-D-galactopyranoside residues in cells; targeted via recombinant Isolectin B4 (IB4), eliminated via saporin. Isolectin B4 (IB4) is one of a family of five alpha-D-galactose-binding lectins from Griffonia (Bandeiraea) simplicifolia. Recombinant IB4* was expressed in E. coli and purified using affinity chromatography. In one important application rIB4-SAP specifically eliminates the IB4-positive c-fiber nociceptor neurons, while sparing the peptidergic neurons. Upon binding the alpha-D-galactopyranoside residues expressed on the cell surface, rIB4-SAP becomes internalized and saporin inhibits protein synthesis, resulting in elimination of the neurons.
rIB4-SAP eliminates a-D-galactosyl-positive cells. All other cells are left untouched.