Systemic administration of IGF-I enhances healing in collagenous extracellular matrices: evaluation of loaded and unloaded ligaments.

Background: Insulin-like growth factor-I (IGF-I) plays a crucial role in wound healing and tissue repair. We tested the hypotheses that systemic administration of IGF-I, or growth hormone (GH), or both (GH+IGF-I) would improve healing in collagenous connective tissue, such as ligament. These hypotheses were examined in rats that were allowed unrestricted activity after injury and in animals that were subjected to hindlimb disuse.

Adjuvant neuropeptides can improve neuropathic ligament healing in a rat model.

Diminished healing in neuropathic tissues suggests an important regulatory role for peripheral neurogenic factors in connective tissue healing. Although neurogenic factors, including neuropeptides, can induce cell proliferation and influence inflammatory cell chemotaxis in vitro, there is little appreciation of the potential of neuropeptides to affect connective tissue healing in vivo. We created both efferent and afferent peripheral neuropathies in 55 female Wistar rats.