THE EFFECTS OF AGE, GH AND IGF-1 ON NEUROMUSCULAR RECOVERY FOLLOWING NERVE TRANSECTION

Age is the single most important determinant of recovery after peripheral nerve injury. With aging, there is a decrease in circulating levels of growth hormone (GH) and insulin-like-growth factor 1 (IGF-1). The purpose of this research was to examine the effect of age, GH and IGF-1 on neuromuscular recovery after peripheral nerve injury in aged rats. It was found that with aging, there is a significant impairment in neuromuscular recovery after peripheral nerve injury and repair. There was a significant impairment in the response of the neuromuscular junction (NMJ) to peripheral nerve injury. Using a dwarf rat model of GH-deficiency, it was found that a lack of circulating GH does not lead to impairments in neuromuscular recovery after nerve injury. Replenishment of GH in aged or GH-deficient rats does not affect neuromuscular recovery. Lastly, it was found that IGF-1, locally-delivered to the site of the regenerating nerve, improved neuromuscular recovery after injury in aged rats. Overall, these results emphasize the role of the NMJ in age-related decline in neuromuscular recovery after peripheral nerve injury and suggest that alterations in local regenerative mechanisms are more important than changes in the systemic GH-IGF-1 axis.

Grantor dc:publisher

Wake Forest University

Year dc:date.issued

2011

Author dc:creator

• Apel, Peter J.

• Aging

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10339/33416

OAI identifier oai:identifier

oai:wakespace.lib.wfu.edu:10339/33416