Animals

To avoid interanimal variability that would be introduced due to differences in the stage of estrous in females, male mice were used. Male C57BL/6 mice (∼12–14 wk) bred on-site or purchased from Harlan were housed under controlled conditions (12 h light, 12 h dark cycle at 21°C) with unrestricted access to standard rodent chow and water. All experiments on animals were approved by the local ethics committee and were performed in accordance with the UK Home Office Animals (Scientific Procedures) Act of 1986.