The toxicity of carbon tetrachloride (CCl(4)) and certain other chemicals varies over a 24-h period. Because the metabolism of some drugs follows a diurnal rhythm, it was decided to investigate whether the hepatic metabolic activation of CCl(4) was rhythmic and coincided in time with maximum susceptibility to CCl(4) hepatotoxicity. A related objective was to test the hypothesis that abstinence ...

19 Daily variation in the absorption, metabolism and excretion of toxic substances will 20 ultimately determine the actual concentration to which the cells and tissues are exposed. In 21 aquaculture, Atlantic salmon (Salmo salar) can be frequently exposed to hydrogen peroxide 22 (H 2 O 2) to treat topical skin and gill infections, particularly in relation to parasitic infections 23 (e.g. sea li...

a r t i c l e i n f o Keywords: Sparus aurata Video-tracking Swimming activity Chronotoxicity MS-222 Anaesthesia Fish are frequently exposed to anaesthetics since their use is necessary in several aquaculture procedures. The aim of this study was to investigate the existence of day–night differences in the toxicity and effectiveness of a common fish anaesthetic (MS-222) in juvenile gilthead sea...