Full text
| |
| Author(s): |
Francisco Carlos Pereira
Total Authors: 1
|
| Document type: | Doctoral Thesis |
| Press: | São Paulo. , gráficos, ilustrações, tabelas. |
| Institution: | Universidade de São Paulo (USP). Instituto de Psicologia (IP/SBD) |
| Defense date: | 1999-01-20 |
| Examining board members: |
Ciro Ferreira da Silva;
Jackson Cioni Bittencourt;
Marcos Raimundo Gomes de Freitas;
Antonio Joao Tedesco Marchese;
Rames Mattar Junior
|
| Advisor: | Ciro Ferreira da Silva |
| Field of knowledge: | Humanities - Psychology |
| Indexed in: |
Banco de Dados Bibliográficos da USP-DEDALUS;
Index Psi Teses - IP/USP |
| Location: | Universidade de São Paulo. Biblioteca do Instituto de Psicologia; QP361; P436a |
| Abstract | |
We studied the actions of exogenous ciliary neurotrophic factor (CNTF) and interleukin-6 (IL-6) on peripheral nerve regeneration. The sciatic nerve of 12 adult C57BL/6J mice (3 groups; n=4) w a s transected and both proximal and distal nerve stumps were secured by a single 10-0 suture into a 6-mm of a polyethylene tube (PT) (0,76 mm ID) to give a final gap length of 4mm. The PT were implanted empty or filled with one of the following solutions: (1) a purified preparation of collagen (Vitrogen, 2,4 mg/ml) plus phosphate buffer solution (0,2M), in 1:1 ratio; (2) Vitrogen + human recombinant CNTF (1:1, with 100 ng/ml of CNTF/tube). After 6 weeks the tubes containing the regenerated nerve cables (NC) were processed for Epon embedding. Myelinated nerve fibers were counted from the mid-portion of the cab les with a computer-controlled system (Biographics). CNTF injected mice regenerated significantly more myelinated axons (3027±62, mean±SEM) compared to the animals implanted with tubes left empty (1384±128) or filled with collagen alone (1639±104). Next, 12 additional animals had the sciatic nerve transected and repaired a s above. After 6 weeks, HRP was applied to the distal stump of the regenerated nerves and labeled neurons were counted in the spinal cord an d L4.5.6 dorsal root ganglia (DRG). No significant difference in the number of motoneurons was detected between the experimental (empty=740±21; collagen=749±44; CNTF=790±14) and non-operated (794±30) animals. No difference was also found in the n umber of labeled DRG neurons among the experimental groups (empty=1920±59; collagen=2262±152; CNTF=2124±96) and all had fewer labeled sensory neurons compared to the non-operated group (4211+96). For the IL-6 experiments, 12 C57BL/6J mice were divided into 2 groups (n=6) and implanted with PT filled with one of the following solutions: (1) Vitrogem (2,4 mg/ml) plus phosphate buffer solution (0,2 M), in 1:1 ratio; (2) Vitrogen + murine recombinant IL-6 (1:1, with 100 |ig/ml of IL-6/tube). Following a survival time of 6 weeks, the tubes with the regenerating nerve cables were processed for Epon embedding and myelinated nerve fiber counting. The results showed a significant difference in the number of myelinated axons between the collagen+IL-6 group (2025±143) and the collagen alone group (1542±122). The L5 DRG was also removed from the same mice, and serially sectioned (5^m) for sensory neuron counts. No significant difference was found in the number of DRG neurons between the experimental groups (collagen=528±42; collagen+IL-6=554±37). However, all had significantly fewer sensory neurons compared to the non-operated group (1112+63). These results indicate that locally applied CNTF and IL-6 stimulate peripheral nerve regeneration in adult animals, and that the effects are due to a neurite-promoting activity on axotomized neurons (AU) | |