The Inflammatory Response and Hyaluronan Synthases in the Rabbit Flexor Tendon and Tendon Sheath Following Injury

Abstract

Using a rabbit model of flexor tendon injury, mRNA levels for a subset of relevant molecules involved in inflammatory and fibrotic processes were assessed by reverse transcriptase-polymerase chain reaction 3, 6, 12 and 24 days after injury. Increased levels of COX-2, IL-1beta, MMP-13 and TIMP-1 mRNA were detected in both tendon and tendon sheath following injury, with each molecule exhibiting tissue and time-dependent changes. MMP-13 and TIMP-1 mRNA levels were markedly upregulated in both tissues, whereas COX-2 and IL-1beta predominantly increased in tendon. Both hyaluronan synthase (HAS) 2 and 3 exhibited increases in mRNA levels in tendon tissue after injury, HAS 2 being more pronounced. These findings support the concept that healing in the flexor tendon and the sheath involve different molecular events and that each tissue may require unique modifications if healing is to be enhanced and adhesions reduced.

Molecular Events of Cellular Apoptosis and Proliferation in the Early Tendon Healing Period

“…This supports the notion that the epitenon, in which cellular proliferation is active during tendon healing, is the most biologically active tendon component. [31][32][33] The findings of this study have implications for understanding the biology of tendon healing. Unlike necrosis, apoptosis is a programmed process.…”

Neuropeptide, Mast Cell, and Myofibroblast Expression After Rabbit Deep Flexor Tendon Repair

“…An animal model of flexor tendon injury described previously 14 was used, with the approval of the local ethics review board. Thirty-five female, young adult New Zealand white rabbits, weighing 3 kg (Ϯ0.3 kg) were divided into 5 groups, including one control group.…”

PXL01 in sodium hyaluronate results in increased PRG4 expression: a potential mechanism for anti-adhesion

“…The surgical procedures were performed during anesthesia with fentanyl-fluanisone (0.3 mL/kg body weight; Hypnorm, Janssen, Beerse, Belgium) and midazolam (2 mg/kg body weight; Dormicum, Roche, Basel, Switzerland) under sterile conditions as described previously (17,18), and all efforts were made to minimize suffering. A prophylactic intravenous dose of the antibiotic cefuroxime (100 mg; Zinacef, GlaxoSmithKline, London, United Kingdom) was given before surgery.…”

“…Buprenorfin (0.1 mg/kg body weight; Temgesic, RB Pharmaceuticals, Slough, United Kingdom) was given postoperatively to prevent pain. The surgical procedures were performed on both hind paws identically, as described previously (17,18). Briefly, to decrease the tensile load on the flexor tendon’s phalangeal section, a partial division of the tendons was performed at the tendon–muscle transition.…”