The effects of a single injection of dexamethasone-21-isonicotinate on the lymphocyte functions of dairy cows at two weeks post partum

Abstract

-Dexamethasone is a potent therapeutic for treatment of the fatty liver syndrome or primary ketosis in post partum dairy cows. Reservations exist, however, among practitioners with respect to the risk of immunosuppression induced by corticosteroids. The aim of this study was to investigate the effect of a single injection of dexamethasone-21-isonicotinate on distinct immune functions of postpartum dairy cows because only scarce information is available on the effects of corticosteroid preparations when administered at a dosage and frequency for treatment of the fatty liver syndrome or primary ketosis. Sixteen Swedish red-pied dairy cows, between days 9 and 15 post partum, were allotted to either a control group (n = 8) or a treatment group (n = 8). The cows in the treatment group received a single intramuscular injection of a dexamethasone-21-isonicotinate suspension at a dosage of 0.02 mg/kg i.m. at the start of the experiment. White blood cell counts and selected lymphocyte functions (lymphocyte proliferation, expression of lymphocyte markers and the β2 and α4 chain of adhesion molecules belonging to the integrin family) and some parameters of the energy metabolism (glucose, insulin) were determined before the administration of corticosteroids (day 0) and subsequently at days 2, 4, 7 and 9 of the experiment. Changes in glucose and insulin were within the target range for treatment of the fatty liver syndrome or primary ketosis. Significant (P < 0.05) increases in the number of circulating white blood cells were observed in treated cows on the second day following treatment which was exclusively caused by an increase in the number of circulating neutrophils. Lymphocyte blastogenesis in response to ConA and the percentages of lymphocytes positive for CD2, CD4, CD8, CD49d and CD18 as well as the intensity of CD49d expression did not differ between the treatment and control groups. There was, however, a significant reduction (P < 0.01) in the intensity of CD18 expression on lymphocytes in the treated animals on the fourth day after treatment. In conclusion, a single administration of dexamethasone-21-isonicotinate in a dosage of 0.02 mg/kg i.m. at two weeks post partum in healthy cows had a significant but highly transient effect on CD18 expression on lymphocytes and the number of peripheral blood neutrophils, but did not affect lymphocyte blastogenesis or lymphocyte subpopulation patterns in peripheral blood.

Effect of single dose dexamethasone administration on metabolism related parameters in lactating fat tailed sheep

“…This was in accordance with earlier studies where glucocorticoid injection resulted in a maked increase in fasted sheep (Fürll and Knobloch, 1994), goats (Sandner et al, 1990) and cattle (Thanasak et al, 2004). Glucocorticoids proven to result in hyperglycaemia through stimulation of gluconeogenesis and reduction of glucose consumption by blocking glucose uptake.…”

“…Fürll and Knobloch (1994) stated a considerable increase in glucose and insulin concentrations after dexamethasone injection in sheep fasted for five days. Thanasak et al (2004) also reported an increase in glucose and insulin levels after a single dose in cattle. Sander et al (1990) reported a 200 fold increase in insulin level in fasted goats after dexamethasone administration.…”

Effect of single dose dexamethasone (0.1 mg/kg) on white blood cell counts and serum glucose levels in healthy ewes

“…In fact, effect of dexamethasone on the WBC counts may depend on dose or animal kinds. Increased WBC counts were reported in female turkeys after dexamethasone treatment, but similar effect of dexamethasone was not observed in males (Huff et al 2015), and increased WBC counts were determined in cows (Thanasak et al 2004). These results may indicate dexamethasone directly affect WBC level in sheep and has no effect other hemogram values.…”

Administration of dexamethasone per os in finishing bulls. II. Effects on blood parameters used as indicators of animal welfare

“…As a corticosteroid, dexamethasone affects the HPA axis (Rijnberk and Mol, 1997), and several studies conducted on cattle and veal calves have shown that such molecules might lead to leukocytosis, neutrophilia, eosinopenia, lymphopenia and monocytosis, as well as to an increase in the Neu/Lym ratio (Lan et al, 1995;Anderson et al, 1999;Thanasak et al, 2004). Oldham and Howard (1992) have shown that daily intramuscular injections of dexamethasone at 0.5 mg/kg per day in calves for 20 days resulted in neutrophilia and lymphopenia.…”