High doses of MPSS have been used to treat dogs and humans with acute spinal cord injuries caused by trauma or intervertebral disk protrusion.1–3 Spinal cord injuries, including intervertebral disk disease, are common clinical problems in dogs and are frequently encountered in small animal practice. High-dose treatments with MPSS can effectively induce rapid neurologic recovery in animals with experimentally induced and naturally occurring spinal cord traumas.2–5 Unfortunately, glucocorticoid treatments can also cause undesired adverse effects, such as delayed wound healing, immunosuppression, and gastric ulcers.2,4,6,7 Immunosuppression is considered one of the most serious problems with regard to clinical relevance because experiments in humans have revealed an increased risk of infections associated with MPSS treatment.8 Neutrophils (ie, PMNs) are the most abundant leukocytes in the blood, and their active participation in the host innate immune defense is clearly established. However, when glucocorticoids are used as part of a treatment regimen,3 their immunosuppressive effects on PMNs (determined in both in vitro9–11 and in vivo12 studies) are regarded as undesirable. High doses of MPSS have been used to treat dogs in clinical situations; however, to our knowledge, the effect of high-dose MPSS treatment on canine PMN functions has not been investigated. The study reported here was conducted to evaluate the effects of high-dose MPSS treatment on selected PMN functions in healthy dogs.
Hank's balanced salt solution
Mean fluorescent intensity
Methylprednisolone sodium succinate
Polymorphonuclear neutrophilic leukocyte
Reactive oxygen species
Solumedrol, Pfizer, NY.
Sigma-Aldrich Co, St Louis, Mo.
Dextran T-500, Wako Pure Chemical Industries, Osaka, Japan.
Ficoll-hypaque, Sigma-Aldrich Co, St Louis, Mo.
Gibco, Grand Island, NY.
Fetal bovine serum, Sanko Junyaku, Ibaragi, Japan.
AbD Serotec, Oxford, England.
Expo 2000 software, Beckman Coulter Inc, Fullerton, Calif.
Fluoresbrite carboxy YG 1.0 micron microspheres, Polysciences Inc, Warrington, Pa.
Epics flow cytometer, Beckman Coulter Inc, Fullerton, Calif.
Phalloidin-fluorescein isothiocyanate, Sigma-Aldrich Co, St Louis, Mo.
Zymosan A, Sigma-Aldrich Co, St Louis, Mo.
Luminol, Sigma-Aldrich Co, St Louis, Mo.
Horseradish peroxidase, Sigma-Aldrich Co, St Louis, Mo.
Dynex Technologies, Chantilly, Va.
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