2.3. Echocardiographic Analysis
Echocardiography (ECHO) was performed blindly under ketamine hydrochloride and xylazine (75 and 5 mg/kg, respectively, i.p.) anesthesia in all groups immediately after the last JWH-018 injection. After the anterior chest wall was shaved in all animals, a transthoracic ECHO was done in a supine position by a researcher (cardiologist, N.E.) who was blinded to the experimental groups. Using a 10-MHz linear transducer probe (GE 10s parallel Design Inc. Phoenix, USA) and a commercially available ECHO system (Vivid 3; GE Healthcare, Phoenix, USA), standard two-dimensional (2D) and M-mode long- and short-axis (at the midpapillary level) imagines were recorded. Heart rate (HR), left ventricular fractional shortening (LVFS), left ventricular ejection fraction (LVEF), early diastolic filling signal (E), atrial contraction signal (A), mitral valve E/A ratio, E wave deceleration time (EDT) were measured and compared among the groups by N.E.