Alteration of the material properties of the normal supraspinatus tendon by nicotine treatment in a rat model

Abstract

Background and purposeSeveral studies have shown that nicotine has a detrimental effect on the development of rotator cuff tear. However, little is known about its mechanism. We evaluated the effect of nicotine on the maximum tensile load, the maximum tensile stress, and the elastic modulus of the supraspinatus tendon in a rat model.Methods27 rats were randomly assigned to 3 groups. Subcutaneously implanted osmotic pumps delivered two different concentrations of nicotine solution (high dose: 45 ng/mL; low dose: 22.5 ng/mL) or saline solution (controls) over a 12-week period. The level of serum cotinine, a breakdown product of nicotine, was evaluated. We performed tensile testing using the left supraspinatus tendon in each rat. The maximum load of the supraspinatus tendon was measured, and the maximum tensile stress and elastic modulus were calculated.ResultsSerum cotinine levels showed controlled systemic release of nicotine. The maximum tensile load and stress were similar in the three groups. The elastic modulus was, however, higher in the nicotine groups than in the control group.InterpretationIn a rat model, ncotine caused a change in the material properties of the supraspinatus tendon. This change may predispose to a tear in the supraspinatus tendon.

Effects of Cigarette Smoking on Elastographic Strain Ratio Measurements of Patellar and Achilles Tendons

“…In previous studies, a decrease in the elastic modulus of the gastrocnemius tendon was detected during stretching exercises. Thus, a decrease in tendon injuries along with stretching exercises has been assumed to correlate with a decrease in the elastic modulus of the tendon 10 , 27 . In addition, supraspinatus tendon tears that initiate at the anterior third of the tendon, where the elastic modulus is higher than at the posterior and middle thirds, have been reported 28 , 29 .…”

“…The elastic modulus of the supraspinatus was found to be higher in high‐ and low‐level nicotine exposure groups in comparison to the control group. Accordingly, Ichinose et al 10 postulated that the increase in the elastic modulus as a result of nicotine might predispose the individual to an increase in tendon injuries. However, they also reported that the nicotine dosage applied to the animals was considerably higher in comparison to the exposure levels of smoking individuals and that their findings should be confirmed with in vivo studies.…”

“…Postoperative knee laxity in heavy smokers who underwent anterior cruciate ligament reconstruction was found to be higher than in nonsmokers, and cessation of smoking 1 month before surgery decreased this effect 9 . The vasoconstrictive effect of nicotine, resulting in tissue ischemia related to a decrease in prostaglandin synthesis, in chronic heavy smokers has also been studied previously 10 . Furthermore, increased collagen synthesis in beagles and increased cross‐linked collagen content, which causes fibrosis in interstitial myocardial tissue due to the effects of nicotine, have also been reported in the literature 11 , 12 .…”

What is the Role of Systemic Conditions and Options for Manipulation of Bone Formation and Bone Resorption in Rotator Cuff Tendon Healing and Repair?

“…has also demonstrated alterations in biomechanical properties of the supraspinatus tendon in the setting of nicotine, producing increased elastic modulus of the supraspinatus tendon in a rat model, an indicator for increased stiffness which is more predisposed to injury. 97 Nicotine has been reported to elevate collagen synthesis and increased collagen cross-linking in animal models. These processes may lead to increased tissue fibrosis and subsequent higher elastic modulus.…”

Nível De Dependencia a Nicotina E Força Muscular Periférica Em Tabagistas

“…Além disso, o estudo de Ichinose et al 20 em 2010 revelou que existe uma redução na produção de oxido nítrico e aumento na síntese de colágeno em ratos expostos a fumaça, fatores que podem contribuir para lesões de tendões musculares devido ao aumento da sua elasticidade 20 . Por este motivo, se faz necessária a mensuração da FMP nesta população, para guiar os profissionais de saúde quanto as suas práticas clinicas.…”