Zdf lean rats

Male ZDF rats (ZDF, n = 12) and the control strain ZDF Lean rats (Lean, n = 12); Charles River, USA) were housed in groups of 2 or 3 in the University of Nottingham Biomedical Services Unit with a 12 h light/dark cycle, a temperature of 22 ± 2°C, and access to Purina 5008 chow and water ad libitum. Rats were treated for 7 days (daily i.p. injection) with either 10 mg/kg CBD or vehicle (in a volume of 1 ml/kg; n = 6 per group). This dose was chosen based on other positive studies with CBD in diabetic models which have used 5 (Weiss et al., 2008 (link)), 10 (El-Remessy et al., 2010 (link); Toth et al., 2010 (link)), or 20 (Rajesh et al., 2010 (link); Toth et al., 2010 (link)) mg/kg. Pure CBD was dissolved in a vehicle of 3:1:16 solution of ethanol: Tween 80: 0.9% Saline. All procedures were in accordance with the UK Home Office Animal (Scientific Procedures) Act 1986. Following the treatment period, the rats (aged 12–13 weeks old) were stunned by a percussive blow to the head, and killed by cervical dislocation. Post-mortem blood samples were collected, and serum extracted by centrifugation (1000 g for 10 min) and then frozen (-80°C) for later use. Blood glucose concentrations were measured using an Accu-Chek Aviva blood glucose monitoring system (Roche Diagnostics Ltd., Mannheim, Germany).

Male 12-week-old Sprague-Dawley (SD; Charles River, Sulzfeld, Germany), Zucker Diabetic Fatty (ZDF), and ZDF lean rats (Charles River, Kingston, NY) were housed in a room at 22 ± 2°C under 12-h light/dark cycles. Sprague-Dawley rats were fed a standard laboratory rat diet and ZDF rats a diet of Purina 5008 as recommended by the supplier and water ad libitum. The rats were acclimatized for at least 1 week before the experiments. All animals received humane care in compliance with the Principles of Laboratory Animal Care formulated by the National Society for Medical Research and the Guide for the Care and Use of Laboratory Animals prepared by the Institute of Laboratory Animal Resources and published by the National Institutes of Health (NIH Publication no. 86-23, revised 1996). This investigation was reviewed and approved by the appropriate institutional review committee.