Cardioprotective Effects of CS and CZ

Male Wistar rats of 300–350 g were used. They were provided by the Laboratory Animal Care of the National Institute of Cardiology “Ignacio Chávez” in México. All procedures for handling animals were approved by the Institutional Ethics Committee and in accordance with the National Rules for the care and handling of experimental animals (SAGARPA, NOM-062-ZOO-1999). The animals were kept under optimal conditions of temperature and light (12 h light/dark) with a standard diet (Lab diet 5012, PMI Nutrition International, Richmond, IN, USA) and water ad libitum. The experimental animals were randomly grouped as follows: 1.—Control; 2.—CS treatment (final dose of 20 mg/kg which was distributed over 4 days); 3.—CZ treatment (final dose of 24 mg/kg distributed over 4 days) and 4.- CZ+CS treatment for 4 days. The CZ was applied first and, an hour later, the CS was injected. CS was applied at a lower dose (20 mg/kg) than that reported by Zhou et al. and by Szabados et al. [18 (link),23 (link)] to avoid deletion of nerve endings and also because we performed a curve dose response in previous experiments with CS and CZ in isolated hearts [24 (link)]. The application of the drugs was through a s.c. injection.