Corticosteroid Fludrocortisone Acetate Targets Multiple End Points in Zebrafish (Danio rerio) at Low Concentrations.

Synthetic corticosteroids may pose an environmental risk to fish. Here, we describe multiend point responses of adult zebrafish (8 months old) upon 21-day exposure to a commonly prescribed corticosteroid, fludrocortisone acetate (FLU), at concentrations between 0.006 and 42 µg/L. No remarkable reproductive impacts were observed, while physiological effects, including plasma glucose level and blood leukocyte numbers were significant altered even at 42 ng/L. Ovary parameters and transcriptional analysis of hypothalamic-pituitary-gonadal-liver axis revealed negligible effects. Significant alterations of the circadian rhythm network were observed in the zebrafish brain. Transcripts of several biomarker genes, including per1a and nr1d1, displayed strong transcriptional changes, which occurred at environmental relevant concentrations of 6 and 42 ng/L FLU. Importantly, the development and behavior of F1 embryos were significant changed. Heartbeat, hatching success and swimming behavior of F1 embryos were all increased even at 6 and 42 ng/L. All effects were further confirmed by exposure of eleuthero-embryos. Significant transcriptional changes of biomarker genes involved in gluconeogenesis, immune response and circadian rhythm in eleuthero-embryos confirmed the observations in adult fish. Hatching success, heartbeat, and swimming activity were increased at 81 ng/L and higher, as with F1 embryos. These results provide novel insights into the understanding of potential environmental risks of corticosteroids.

Experimental cardiac hypertrophy induced by oral administration of mineralocorticoid and saline in rats.

We suggest a new, easily applicable way of myocardial hypertrophy induction in rats. Forty randomized age-matched male Wistar rats were divided into 2 groups of 20 each: a control group and an orally administered fludrocortisone/salt group. Myocardial hypertrophy was estimated by measuring body weight, heart-weight-to-body-weight ratio and ventricular free wall thickness. Moderate myocardial hypertrophy without heart failure was established in fludrocortisone/salt group in 4 weeks. Our method is effective and low cost, and it provides a model of hypertrophic heart.

[Investigations of the ototoxicity of dicortinef (ear drops)]. / Badania ototoksycznosci preparatu Dicortinef (krople do uszu).

The authors investigated the ototoxic influence of Dicortinef in laboratory animals. Their examinations were performed on 15 guinea pigs (weighing 210-380 g.) after application of this medicine to the fenestra rotunda. The harmful effect of Dicortinef was expressed by the characteristic fall in the microphonic potential (PM) and potential of the acoustic nerve (AP).