Physiological and Behavioral Effects of Exposure to Environmentally Relevant Concentrations of Prednisolone During Zebrafish (Danio rerio) Embryogenesis.
The presence of synthetic glucocorticoids within the aquatic environment has been highlighted as a potential environmental concern as they may mimic the role of endogenous glucocorticoids during vertebrate ontogeny. Prednisolone is a commonly prescribed synthetic glucocorticoid which has been repeatedly detected in the environment. This study investigated the impact of environmentally relevant concentrations of prednisolone (0.1, 1, and 10 μg/L) during zebrafish embryogenesis using physiological and behavioral end points which are known to be mediated by endogenous glucocorticoids. The frequency of spontaneous muscle contractions (24 hpf) was significantly reduced by prednisolone and 0.1 μg/L increased the distance embryos swam in response to a mechanosensory stimulus (48 hpf). The percentage of embryos hatched significantly increased following prednisolone treatment (1 and 10 μg/L), while growth and mortality were unaffected. The onset of heart contraction was differentially affected by prednisolone while heart rate and oxygen consumption both increased significantly throughout embryogenesis. No substantial effect on the axial musculature was observed. Morphological changes to the lower jaw were detected at 96 hpf in response to 1 μg/L of prednisolone. Several parameters of swim behavior were also significantly affected. Environmentally relevant concentrations of prednisolone therefore alter early zebrafish ontogeny and significantly affect embryo behavior.
Institute of Biomedical and Environmental Health Research, School of Science and Sport, University of the West of Scotland , Paisley, U.K.
Paul L
PL
McNeil
Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Veterinary Medicine, University of Santiago de Compostela , Lugo, Spain.
Carolina
C
Nebot
Institute of Biomedical and Environmental Health Research, School of Science and Sport, University of the West of Scotland , Paisley, U.K.
Katherine A
KA
Sloman
D000818:Animals; D004625:Embryo, Nonmammalian / Q000187:drug effects; D047108:Embryonic Development / Q000187:drug effects; D005938:Glucocorticoids; D011239:Prednisolone; D015027:Zebrafish
D005938:Glucocorticoids; D011239:Prednisolone