Functional Recovery of Rat Hind-Limb Allografts

Abstract

Few papers have assessed the long-term functional recovery of animal limb allografts. In this study, the functional recovery of rat limb allografts was serially and quantitatively investigated for a period of 1 year. The donor's hind limb was orthotopically transplanted into the recipient. Fifteen recipients with allografts were treated with FK506. Functional recovery of the grafted limb was assessed serially by cutaneous reaction test, walking track analysis, and electrophysiologic evaluation. Sensibility improved to a similar extent in both isografts and allografts, and the recovery rate at 1 year was 68 percent, compared to the normal side. Sciatic function index significantly improved to - 70 points after 1 year. The amplitude recorded from the gastrocnemius muscle significantly improved, and the ratio compared to the normal side was 43 percent. Limb isografts and allografts treated with FK506 showed no significant differences in functional recovery. The data can be used as a reference standard for future investigations.

Administration of low-dose FK 506 accelerates histomorphometric regeneration and functional outcomes after allograft nerve repair in a rat model

“…Thus, FK 506 could be useful, even clinically, for enhancing regeneration after surgical repair by improving the rate of axonal growth with allografts. In fact, there are reports of positive results regarding nerve regeneration in animals and humans immunosuppressed by FK 506 (Gold et al, 1994;Berger and Lassner, 1994;Mackinnon et al, 2001;Yang et al, 2003;Martin et al, 2005;Song et al, 2005;Snyder et al, 2006). Although previous studies found that FK 506 is maximally effective when administered in high doses (5e10 mg/kg/day) during the entire regeneration period in rat sciatic nerve models (Wang et al, 1997;Udina et al, 2004), prolonged systemic immunosuppression might not be justified for ensuring the success of nerve regeneration.…”

Sensorimotor Recovery After Partial Facial (Mystacial Pad) Transplantation in Rats

“…A period of 6 weeks was enough to observe reinnervation, but longer periods would probably improve the quality of reinnervation. 40 (3) Return of the motor activity of the mystacial muscles as demonstrated by EMG does not necessarily correlate with normal whisking, and the whiskers spatial orientation was altered due to scarring. (4) Pulling the whiskers is not a validated test for sensory recovery, although it gives qualitative evidence of reinnervation, and similar sensitivity tests have been accepted for publication.…”

“…However, this result does not invalidate our findings because the reinnervation of an isotransplant versus an allotransplant was not the scope of our work. Moreover, in a clinical scenario there would be no possibility to choose between a replantation (isotransplant) and a transplantation (allotransplant) because the former has the advantage of avoiding the use of immunosup- 40 and that we only waited 6 weeks before performing neurophysiological tests since this period was enough to reinnervate hind-limb allografts. 43 This report underlines the return of function to a sensorimotor facial subunit transplant.…”

Allografting Combined with Systemic FK506 Produces Greater Functional Recovery than Conduit Implantation in a Rat Model of Sciatic Nerve Injury

“…Moreover, the immunosuppressive drug FK506 has been shown to have neuroprotective and neurotrophic action in experimental models both in vitro and in vivo. [4][5][6][7][8][9][10] Thus, FK506 could be useful in the clinic to enhance regeneration following surgical repair with both autografts and allografts.…”