Evaluation of the function of polymorphonuclear neutrophilic leukocytes in healthy dogs given a high dose of methylprednisolone sodium succinate.
OBJECTIVE
To evaluate effects of a high dose of methylprednisolone sodium succinate (MPSS) on function of polymorphonuclear neutrophilic leukocytes (PMNs) in dogs.


METHODS
7 healthy male Beagles (body weight, 10.5 to 15 kg; age, 2 to 4 years).


METHODS
All dogs were treated by IV administration of a high dose of MPSS (30 mg/kg). Additional doses of MPSS (15 mg/kg) were administered IV at 2 and 6 hours and then at 6-hour intervals until 48 hours after the initial dose. Blood samples were collected before and 1, 2, 4, 7, and 14 days after completion of the MPSS administrations and used for evaluation of PMN functions. Isolated PMNs were used for assessment of functions, such as adhesion, migration, phagocytosis, and oxidative burst.


RESULTS
On days 1, 2, and 4 after completion of MPSS administration, there was a decrease in PMN expression of adhesion markers such as CD11b and CD18. There was a decrease in the phagocytotic ability of PMNs on days 1, 2, and 7 after completion of MPSS administration, with a reduction in the oxidative burst of PMNs detected on day 7. No significant changes were identified for migration. All functional changes returned to their pretreatment values by 14 days after completion of MPSS treatment.


CONCLUSIONS
Treatment with a high dose of MPSS suppressed PMN functions in dogs. Analysis of these results suggested that treatment with a high dose of MPSS can suppress some of the major functions of PMNs for at least 7 days.
Shimamura
Shunsuke
S
School of Veterinary Medicine, Kitasato University, 35-1 Higashi 23 Ban-cho, Towada-shi, Aomori 034-8628, Japan. shimamur@vmas.kitasato-u.ac.jp
Kanayama
Kozue
K
Shimada
Takuya
T
Maeda
Kenichi
K
Nakao
Ruriko
R
Kobayashi
Saori
S
Sato
Reeko
R
Okano
Shozo
S
D000199:Actins / Q000097:blood / Q000187:drug effects; D000818:Animals; D018845:CD11 Antigens / Q000187:drug effects / Q000235:genetics; D004285:Dogs; D005434:Flow Cytometry; D049449:Luminescence; D008297:Male; D008776:Methylprednisolone Hemisuccinate / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*; D010587:Phagocytosis / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012016:Reference Values
D000199:Actins; D018845:CD11 Antigens; D017382:Reactive Oxygen Species; D008776:Methylprednisolone Hemisuccinate