Nicolás Vidal-Seguel & Enrique Montiel-Eulefi

In damaged organs, lactic acid (LA) modifies the innate and inflammatory immune response, inducing a lower expression of pro-inflammatory cytokines, which provoke the modulation of immune cell recruitment. Damage by compression of the sciatic nerve (SN) triggers an inflammatory response and an exponential increase in the inflammatory infiltrate of immune cells, producing the destruction of axons and functional loss of the nerve. The objective of this study is to evaluate the acute effect of the injection of LA, on the proportion of immune cells in the early inflammatory phase, in the site of SN post-compression injury. For this, 15 adult Sprague Dawley rats were used in three groups of nervous compression. A control group, a negative control group with placebo (100 mL PBS) and an experimental group with injection of 100 mL of LA [20mM]. On the third day, the SNs were histologically analyzed and the proportion of immune cells at the injury site was established. The results show that the intraneural injection of LA causes a decrease in the percentage of lymphocytes and an increase in the percentage of macrophages. This is the first work of intraneural injection of LA and demonstrates the modulating effect of LA on immune cells in the peripheral nervous system.

VIDAL-SEGUEL, N. & MONTIEL-EULEFI, E. Effect of lactic acid on the cellular response of the immune system during the early inflammatory phase in the sciatic nerve damaged by compression. Int. J. Morphol., 37(4):1527-1533, 2019.