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Local administration of thyroid hormones in silicone chamber increases regeneration of rat transected sciatic nerve.
Exp Neurol. 1998 Mar; 150(1):69-81.EN

Abstract

Conflicting actions of the exogenous thyroid hormone on regenerating peripheral nerve have been reported. These contradictory results were probably due to daily intraperitoneal injections which induce a high concentration of thyroid hormone after administration. In our present study we adapted a technique which allows a local administration of thyroid hormones in a closed system. The effect of a single and local treatment with triiodothyronine (T3) on axonal growth across a gap between sectioned ends of sciatic nerve within silicone chambers was examined in Wistar rats. After nerve transection and surgical implantation, silicone chambers were filled with either a neutral pH solution of triiodothyronine dissolved in NaOH or with sterile solvent as control. Regeneration of the nerves was examined 2 to 8 weeks following the surgery. Early regeneration (4 weeks) was studied by morphological analysis of nerves which showed a significant difference between T3-treated and control groups. Morphometric analysis revealed: (1) a significant difference in the mean diameter of myelinated axons between T3-treated nerve (phi 3.80 +/- 0.22 microns) and control (phi 3.07 +/- 0.44 microns); (2) that T3 increased significantly (1.4-fold) the number of myelinated axons that grew into the middle and distal ends of regeneration chambers; (3) that ultrastructural analysis showed significantly higher percentage of myelinated axons per total axon population in T3-treated groups (38.8 +/- 5.9%) as compared to control (16.0 +/- 2.3%); and (4) that the myelinated axons had thicker myelin sheaths. The beneficial effects of T3 on regeneration, observed at 4 weeks, were sustained over a prolonged period of time. Thus, at 8 weeks of regeneration, the number, the mean diameter of myelinated axons, and the thickness of myelin sheaths remained significantly greater in T3-treated groups. Therefore, a single and local administration of thyroid hormone at the level of the transected sciatic nerve is sufficient to rapidly set off several mechanisms which, in turn, produce a stimulating and lasting effect on peripheral nerve regeneration. The beneficial effects of T3 upon injured peripheral nerve may have considerable therapeutic potential.

Authors+Show Affiliations

Institut de Biologie cellulaire et de morphologie, Faculté de Médecine, Université de Lausanne, Switzerland.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

9514821

Citation

Voinesco, F, et al. "Local Administration of Thyroid Hormones in Silicone Chamber Increases Regeneration of Rat Transected Sciatic Nerve." Experimental Neurology, vol. 150, no. 1, 1998, pp. 69-81.
Voinesco F, Glauser L, Kraftsik R, et al. Local administration of thyroid hormones in silicone chamber increases regeneration of rat transected sciatic nerve. Exp Neurol. 1998;150(1):69-81.
Voinesco, F., Glauser, L., Kraftsik, R., & Barakat-Walter, I. (1998). Local administration of thyroid hormones in silicone chamber increases regeneration of rat transected sciatic nerve. Experimental Neurology, 150(1), 69-81.
Voinesco F, et al. Local Administration of Thyroid Hormones in Silicone Chamber Increases Regeneration of Rat Transected Sciatic Nerve. Exp Neurol. 1998;150(1):69-81. PubMed PMID: 9514821.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Local administration of thyroid hormones in silicone chamber increases regeneration of rat transected sciatic nerve. AU - Voinesco,F, AU - Glauser,L, AU - Kraftsik,R, AU - Barakat-Walter,I, PY - 1998/3/26/pubmed PY - 1998/3/26/medline PY - 1998/3/26/entrez SP - 69 EP - 81 JF - Experimental neurology JO - Exp Neurol VL - 150 IS - 1 N2 - Conflicting actions of the exogenous thyroid hormone on regenerating peripheral nerve have been reported. These contradictory results were probably due to daily intraperitoneal injections which induce a high concentration of thyroid hormone after administration. In our present study we adapted a technique which allows a local administration of thyroid hormones in a closed system. The effect of a single and local treatment with triiodothyronine (T3) on axonal growth across a gap between sectioned ends of sciatic nerve within silicone chambers was examined in Wistar rats. After nerve transection and surgical implantation, silicone chambers were filled with either a neutral pH solution of triiodothyronine dissolved in NaOH or with sterile solvent as control. Regeneration of the nerves was examined 2 to 8 weeks following the surgery. Early regeneration (4 weeks) was studied by morphological analysis of nerves which showed a significant difference between T3-treated and control groups. Morphometric analysis revealed: (1) a significant difference in the mean diameter of myelinated axons between T3-treated nerve (phi 3.80 +/- 0.22 microns) and control (phi 3.07 +/- 0.44 microns); (2) that T3 increased significantly (1.4-fold) the number of myelinated axons that grew into the middle and distal ends of regeneration chambers; (3) that ultrastructural analysis showed significantly higher percentage of myelinated axons per total axon population in T3-treated groups (38.8 +/- 5.9%) as compared to control (16.0 +/- 2.3%); and (4) that the myelinated axons had thicker myelin sheaths. The beneficial effects of T3 on regeneration, observed at 4 weeks, were sustained over a prolonged period of time. Thus, at 8 weeks of regeneration, the number, the mean diameter of myelinated axons, and the thickness of myelin sheaths remained significantly greater in T3-treated groups. Therefore, a single and local administration of thyroid hormone at the level of the transected sciatic nerve is sufficient to rapidly set off several mechanisms which, in turn, produce a stimulating and lasting effect on peripheral nerve regeneration. The beneficial effects of T3 upon injured peripheral nerve may have considerable therapeutic potential. SN - 0014-4886 UR - https://www.unboundmedicine.com/medline/citation/9514821/Local_administration_of_thyroid_hormones_in_silicone_chamber_increases_regeneration_of_rat_transected_sciatic_nerve_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0014-4886(97)96732-7 DB - PRIME DP - Unbound Medicine ER -