title: Effect of ropivacaine infiltration on muscle regeneration: a morphometric analysis.
abstract: OBJECTIVE
  Local anaesthetic myotoxicity is a well described phenomenon resulting in reversible muscle damage. Considering that in previous studies microscopic images were evaluated without quantification of morphologic characteristics, the aim of the present study was evaluate muscle regeneration after local anaesthetic infiltration.
  
  
  METHODS
  Wistar rats underwent injection of the left tibialis anterior muscle with ropivacaine (0.75%, group HC or 0.375%, group LC), while the contralateral muscle was injected with saline (group SL). Six weeks later, the muscles were dissected, stained using acid ATPase and examined under light microscope coupled with a computer imaging system for morphometric analysis. Sections were evaluated regarding the content of different muscle fibre types (type I, IIa and IIb), fibre cross-section area and perimeter.
  
  
  RESULTS
  Groups were comparable regarding the ratio of different muscle fibre types. Regenerated type I fibres of both HC and LC groups had significant greater mean cross-sectional area and perimeter, compared to SL fibres. No signs of necrosis or inflammation were observed. Type IIa and IIb fibres didn't show significant differences.
  
  
  CONCLUSIONS
  Regenerated muscles, following local anaesthetic application, showed long-term morphological differences, which could lead to impaired function. Further studies are needed, in order to clarify the underlying cellular mechanisms and the subsequent possible functional impairment.
authors.affiliation: Department of Physiology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: D
authors.initials: D
authors.lastname: Kapoukranidou
authors.affiliation: Department of Anaesthesia and Critical Care, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Amaniti
authors.affiliation: Department of Physiology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: J
authors.initials: J
authors.lastname: Kalpidis
authors.affiliation: Department of Anaesthesia and Critical Care, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: K
authors.initials: K
authors.lastname: Karakoulas
authors.affiliation: Department of Pharmacology School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Papazisis
authors.affiliation: Department of Physiology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: M
authors.initials: M
authors.lastname: Albani
authors.affiliation: Department of Pharmacology School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: D
authors.initials: D
authors.lastname: Kouvelas
keywords: Myotoxicity; morphometry; rat; regeneration; ropivacaine