Effects of dibutyryl cyclic adenosine monophosphate, ACTH(4-10) and gangliosides on nerve fiber regeneration after rat sciatic nerve tubulization.

Tubulization of sectioned rat sciatic nerves was used to evaluate the effect of dibutyryl cyclic adenosine monophosphate (db-cAMP), a fragment of the adrenocorticotrophic hormone (ACTH(4-10] and gangliosides on the regrowth of injured nerve processes. Four weeks post-operative, the number of myelinated fibers was counted at different levels of the lesioned sciatic nerves and the endoneurium surface of the bridging structure in the tube was measured. Animals treated with gangliosides and db-AMPc showed statistically significant differences compared to vehicle treated rats. The gangliosides have shown a beneficial effect but db-cAMP diminished the number of myelinated fibers. In this case, an implication of Schwann cell mitosis and migration is discussed. In spite of better results obtained in ACTH(4-10)-treated animals compared to controls, the differences did not attain a statistically significant level. These experiments confirm the beneficial effect of gangliosides on peripheral nerve regeneration and reveal a negative effect of db-cAMP in the regeneration chamber model.