Abstract
Purpose :
To evaluate anti-inflammatory effect in Type 2 diabetic rats (OLETF) after intravenous Substance P (SP) injection
Methods :
Retinal nerve fiber layer (RNFL) thicknesses were measured manually at 1300 μm from the center of the optic nerve head using SD-OCT. 5nmole/kg Substance P was injected intravenously twice a week from 27 to 30 weeks. Serum inflammatory cytokines, serum liver enzyme concentration, spleen and bone marrow changes were analyzed histologically and immunologically.
Results :
At 28 weeks, RNFL thickness was significantly lower in OLETF than control group. From 29 weeks (2 weeks after injection) RNFL thickness showed significant increase in SP injection group maintained by 31 weeks. In histologic analysis, SP injection group presented decrease of GFAP staining, cell apoptosis, serum liver enzymes and inflammatory cytokines. In the spleen, SP injection group presented decrease of white pulp zone(lymphocyte zone)/total area ratio. In the bone marrow, bone marrow colony forming efficiency was higher than control group. Suppression of fatty marrow progression was observed.
Conclusions :
Substance P injection showed anti-inflammatory effect in retinal neurodegeneration as early change of diabetic retinopathy and in immune reaction of spleen. In bone marrow, SP enhanced activation of mesenchymal stem cells-mediated immune modulation. Therefore, SP might prevent retinal neurodegeneration through systemic anti-inflammatory reaction and stimulation and mobilization of bone marrow cell.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.