Acute and Subacute Effects of Dexamethasone on the Number of White Blood Cells in Rats

Abstract

The purpose of this study was to elucidate the effects of dexamethasone, a synthetic glucocorticoid, on the immune system by analyzing the number of white blood cells (WBCs) over the course of hours and days of dexamethasone administration. Dexamethasone was given as either a single dosage [1.0 mg/kg body weight (BW); subcutaneous injection (s.c.)] or as a daily dosage (1.0 mg/kg BW per day; s.c.) for 10 days for the hourly and daily assessment of changes in the number of white blood cells, respectively. A single administration of dexamethasone markedly decreased the number of total WBCs, as well as the number of lymphocyte, monocyte, neutrophil and eosinophil subsets with a nadir at 8 hr post-injection. The number of these cells recovered to the control levels at 24 hr. The numbers of total WBCs, lymphocytes, monocyte, eosinophil and basophil were reduced by the daily administration of dexamethasone. However, the number of neutrophil was significantly higher at days 2 and 8 after the injection. These results suggest that glucocorticoid-mediated immunosuppressions are at least partly attributable to quantitative changes in the number of circulating WBCs.

Lowering Effects of Allyl Isothiocyanate on the Number of Lymphocyte and Its Subsets in Rats

“…Our recent observations also showed that a single administration of dexamethasone (dose = 1.0 mg/kg body weight) markedly decreased the number of lymphocytes with a nadir at 8 hr of post s.c. injection, and the number of lymphocytes recovered to the normal levels at 24 hr of post s.c. injection. 22) In the present study, we showed that administration of AITC for 4 days increased markedly plasma corticostrone concentrations to 5.4-6.0 times, as compared with the control values (Fig. 5).…”

“…The experiment was performed with the least possible pain of discomfort to the animals. [11][12][13][20][21][22] Administration of AITC to Rats --AITC (purity 95%; Wako Pure Chem. Ind., Osaka, Japan) was dissolved in 2% ethanol and then added 10% Tween 80 and 0.9% NaCl as a vehicle to obtain 0.5% and 1.0% of AITC.…”

“…14,15) Whole blood samples were collected from the tail vein according to our routine method. 21,22) These samples were used for the count analyses of lymphocytes. The number of red blood cells (RBCs), hemoglobin concentration and hematocrit value were also analyzed.…”

Diallyl Disulfide Reduced Dose-Dependently the Number of Lymphocyte Subsets and Monocytes in Rats

“…Thus, increased plasma glucocorticoid levels cause a significant reduction in the circulating number of lymphocytes and monocytes (26). In fact, acute administration of corticosterone and dexamethasone reduced the circulating number of these cells (16,28). Furthermore, glucocorticoids are known to act more sensitively to B-lymphocytes than T-lymphocytes and NK cells (26).…”

Different Recovery Responses from Dietary Zinc-Deficiency in the Distribution of Rat Granulocytes

“…However, the overall responses of the number of white blood cells, and plasma zinc and corticosterone levels in the recovery from dietary zinc-deficiency are still unknown. These questions are of critical importance to understanding of the distribution of white blood cells as an index of the immune-responses of the body defense system (7)(8)(9)(10)(11)(12). In the present study, therefore, we studied the effects of the recovery from dietary zinc-deficiency on the distribution of the number of total white blood cells (WBCs), neutrophils, eosinophils, and basophils, and plasma zinc and corticosterone concentrations in weanling male rats.…”