Clozapine (8-chloro-11-(4-methyl-1-piperazinyl)-5H-dibenzo [b,e] [1,4] diazepine) (Sigma Aldrich, Bayouni Trading Co. Ltd., Al-Khobar, Saudi Arabia) was dissolved in 0.1 M HCl and pH-balanced check details in phosphate-buffered saline (PBS) (Sigma Aldrich, Bayouni Trading Co. Ltd., Al-Khobar, Saudi Arabia). This solution was administered intraperitoneally (i.p.) daily in 0.1-ml doses. All other chemicals used in this study were of analytical grade. The animals used
in this study were young male Wistar rats, 3-4 weeks of age and 120–150 g in body weight, from the animal facility of King Saud University, Riyadh, Saudi Arabia. Animals were housed in groups of 10 rats in standard clear polycarbonate cages, with food and water available ad libitum. Animals were kept on a 12-h light–dark schedule (6:00 am–6:00 pm), and all experimental testing was conducted during the light phase, between 9:00 am and 12:00 pm. All experiments were carried out in accordance with the National Institutes of Health guide for the care and use of laboratory animals (NIH Publications No. 8023, revised 1978). The Institutional Animal Use and Care Committee approved the experimental protocol.
All efforts were made to minimise animal suffering and to reduce the number of animals used. The animals were randomly divided into four groups. Clozapine was administered in doses of 10 (n =10), 15 (n =10) and 25 (n =13) mg/kg/day i.p. for 21 days in three groups. The fourth group (n =10), the control group, was treated with saline. The moderate to high doses of clozapine were based on previous reports . The animal’s body weight (BW) was measured before selleck inhibitor and after the study period. At the end of the study period (21 days), rats were anesthetised with 2% halothane in O2 and subjected to echocardiographic study followed by hemodynamic measurements. At the end of hemodynamic measurements, blood samples were drawn by cardiac puncture. Hearts were excised, washed with ice-cold
saline, blotted with a piece of filter paper, and weighed immediately (HW), and the ratio to BW (HW/BW) was calculated. Hearts were then divided midventricularly into two halves, with one half immediately snap-frozen in liquid nitrogen for subsequent biochemical assays. Ventricles of the second half were used for histological and immunohistochemical Bupivacaine studies. Left ventricular (LV) function analysis was performed via echocardiography and hemodynamic measurement. Two-dimensional echocardiographic studies were performed under 0.5% halothane anaesthesia using an echocardiographic machine equipped with a 7.5-MHz transducer (SSD-5500; Aloka, Tokyo, Japan). M-mode tracings were recorded from the epicardial surface of the right ventricle; the short-axis view of the left ventricle was recorded to measure the LV dimension in diastole (LVDd) and LV dimension in systole (LVDs). LV fractional shortening (FS) and ejection fraction (EF) were calculated and expressed as percentages.