Differential expression of cytokines and nitric oxide synthase isoforms in human rotator cuff bursae

Cytokines have key roles in the induction and effector phases of all immune and inflammatory responses. 2 Cytokines are also key molecules in soft tissue response to injury and wound healing. 3-5 Nitric oxide, a free radical produced by NOSs, is another potent stimulator and mediator of biological processes, including immune and inflammatory responses, as well as wound healing 6 and tendon healing. 7 8 Seventeen patients with shoulder symptoms due to rotator cuff tear were included in the study (table 1 ). The mRNA expression of interleukin 1β (IL1β), IL6, IL8, tumour necrosis factor (TNFα), and granulocyte macrophage colony stimulating factor (GM-CSF), as well as inducible, endothelial, and neuronal isoforms of nitric oxide synthase (iNOS, eNOS, and nNOS) were examined by semiquantitative reverse transcriptase-polymerase chain reaction.