PACAP facilitate the nerve regeneration factors in the facial nerve injury.
Pituitary adenylate cyclase-activating polypeptide (PACAP) has been reported as a strong neurotrophic factor in the various sites of nervous system. The facial nerve injury is one of the common problems in patients at the Otolaryngology since the nerve damage could occur easily due to the anatomical characteristics. Once it happens, the regeneration is little observed and functional recovery is poor. Thus, we investigated that PACAP might have some influence for regeneration after the facial nerve transaction in the guinea pig. PACAP treatment accelerated time for the appearance of compound muscle action potentials (CMAP) after the nerve transaction (first appeared at 1 versus 2 weeks in control) and shortened the latency at 4 weeks. The number of myelinated fibers increased at 4 weeks. Histochemical demonstration of GAP-43, a growth cone protein, was observed at the injury area at 2-4 days. PACAP increased the level of glial cell line-derived neurotrophic factor (GDNF), a neurotrophin, in facial target muscles at 1 day-4 weeks. These data indicated that PACAP promotes the regeneration factors and increases the possibility of functional recovery following the facial nerve injury.
Kimura
Hiromoto
H
Department of Otolaryngology, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan.
Kawatani
Masahito
M
Ito
Eiko
E
Ishikawa
Kazuo
K
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D020220:Facial Nerve Injuries / Q000188:drug therapy* / Q000503:physiopathology; D019922:GAP-43 Protein / Q000378:metabolism; D051100:Glial Cell Line-Derived Neurotrophic Factor; D006168:Guinea Pigs; D007150:Immunohistochemistry; D008297:Male; D009414:Nerve Growth Factors / Q000378:metabolism / Q000494:pharmacology* / Q000502:physiology; D009416:Nerve Regeneration / Q000187:drug effects* / Q000502:physiology; D009469:Neuromuscular Junction / Q000187:drug effects / Q000503:physiopathology; D009479:Neuropeptides / Q000494:pharmacology* / Q000502:physiology; D018377:Neurotransmitter Agents / Q000494:pharmacology* / Q000502:physiology; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide
D019922:GAP-43 Protein; D051100:Glial Cell Line-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide