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

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 b2 and a4 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.

Adrenocorticotropin-corticosterone relationship during dexamethasone therapy in 17 alpha-hydroxylase deficiency

A previous study in an untreated girl with 17 alpha-hydroxylase deficiency syndrome (17-OHDS) indicated that in the absence of cortisol production, ACTH and corticosterone (B) may interact to modulate the brain-pituitary-adrenocortical system. The ACTH-B interplay was further examined in this patient under dexamethasone therapy and after withdrawal of treatment. Plasma ACTH and B were highly correlated (r = 0.89) during two different schedules of dexamethasone treatment and two weeks off treatment at all blood sampling times (morning, afternoon or 24-h period). A logarithmic-sigmoidal relationship seems to exist between ACTH and B secretion. The time course of ACTH-B relationship early after withdrawal of therapy showed good parallelism between these two variables. Plasma B may be a useful guide for monitoring therapy in 17-OHDS. The present study also indicates the ACTH-B interplay feedback set-points.

Therapeutic index of steroid aerosols in asthma. A single-blind comparative trial of beclomethasone dipropionate vs dexamethasone isonicotinate

1) A 4-week single-blind study is reported which compares the responses of 10 matched pairs of adult asthmatic patients to Beclomethasone Dipropionate and Dexamethasone Isonicotinate aerosols, each at 12 metered-doses per day. 2) Therapeutic efficacy was evaluated by measurement of pulmonary function (PEFR) and by a physician's "overall evaluation" scale. 3) Side-effects related to systemic absorption were evaluated by A.M. blood cortisol levels and total eosinophil counts. 4) At the doses studied, Beclomethasone Dipropionate produced both no side-effects and a significant favourable clinical response, while Dexamethasone Isonicotinate produced significant side-effects and a lesser clinical response.