Die Beeinflussung der Regeneration peripherer Nerven durch den β₂-Rezeptor-Agonisten Clenbuterol

Zusammenfassung

Fragestellung

Bei Zellschäden im zentralen Nervensystem zeigt die Applikation von Clenbuterol eine neuroprotektive Wirkung durch die Induktion von Wachstumsfaktoren. Bei Denervation von Skelettmuskeln führt Clenbuterol außerdem zu einer Minderung der Muskelatrophie. Dieser Versuch soll zeigen, ob Clenbuterol auch einen Einfluss auf die Regeneration peripherer Nerven hat.

Methoden und Material

An Versuchsratten wurde der N. ischiadicus vollständig durchtrennt und mikrochirurgisch koaptiert. Je acht Tiere erhielten über einen Zeitraum von vier bzw. sechs Wochen Clenbuterol in einer Dosierung von 100 µg/kg/Tag oral appliziert. Kontrollgruppen erhielten bei gleicher Operation und gleichem Beobachtungszeitraum nur reines Trinkwasser. Die Auswertung erfolgt histologisch, morphometrisch und klinisch. Das Muskelgewicht des M. soleus und des M. extensor digitorum wurde als Ratio zur Gegenseite bestimmt.

Ergebnisse

Die histologische und morphologische Untersuchung zeigten eine signifikant höhere Axonzahl der Clenbuterolgruppen und eine bessere G-Ratio. Das Muskelgewicht war in der Clenbuterolgruppe nach sechs Wochen signifikant erhöht, und in dieser Gruppe konnten mehr Tiere die Zehen spreizen.

Schlussfolgerung

Clenbuterol führt im Tierversuch in einer Dosierung von 100 µg/kg/Tag zu einer positiven Beeinflussung der Regeneration des N. ischiadicus.

Abstract

Purpose

Clenbuterol has shown a neuroprotective action in the central nervous system by induction of growth factors after cellular damage. Additionally, the atrophy of sceletal muscle is attenuated by the application of Clenbuterol after denervation. This experiment was performed to show the influence of Clenbuterol on regeneration of peripheral nerves.

Method and Material

In a rat model, the sciatic nerve was transected and microsurgically coaptated. Eight animals in each group received a daily oral dosage of 100 µg/kg bodyweight during four, respectively six weeks. Two control groups received only drinking water under the otherwise same protocol. The assessment was done histologically, morphometrically and clinically. The weight ratio of the soleus and extensor digitorum muscles of the operated to the contralateral side was measured.

Results

The groups treated with Clenbuterol showed histologically and morphometrically a significantly increased axon count and a better g-ratio. The muscle weight ratio was significantly higher in the Clenbuterol group after six weeks and more animals in this group were able to spread their toes.

Conclusion

The oral application of Clenbuterol in a rodent model shows a positive influence on nerve regeneration.

Schlüsselwörter

Clenbuterol - periphere Nerven - Regeneration - Denervation

Key words

Clenbuterol - peripheral nerves - regeneration - denervation

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