Experimental protocol employed in the present study
| Study no. | Groups | Name of the group | Interventions |
|---|---|---|---|
| 1 | Group I | Normal | Rats were not subjected to any intervention and heart was isolated for biochemical estimations |
| 2 | Group II | Control | Thirty minutes of ischemia and 120 min of reperfusion |
| 3 | Group III | RIPC in young | Forty minutes of remote hind preconditioning stimulus in young rats followed by isolation of heart after 24 h. Thereafter, 30 min of ischemia and 120 min of reperfusion to the isolated heart |
| 4 | Group IV | RIPC in old | Forty minutes of remote hind preconditioning stimulus in aged rats followed by isolation of heart after 24 h. Thereafter, 30 min of ischemia and 120 min of reperfusion to the isolated heart |
| 5 | Group V | NaHS (20 µmol/kg) and RIPC in old | Administration of sodium hydrosulfide (20 µmol/kg i.p.) thirty minutes prior to remote hind preconditioning stimulus, followed by isolation of heart after 24 h. Thereafter, 30 min of ischemia and 120 min of reperfusion to the isolated heart |
| 6 | Group VI | NaHS (40 µmol/kg) and RIPC in old | Administration of sodium hydrosulfide (40 µmol/kg i.p.) thirty minutes prior to remote hind preconditioning stimulus, followed by isolation of heart after 24 h. Thereafter, 30 min of ischemia and 120 min of reperfusion to isolated heart |
| 7 | Group VII | LC (20 mg/kg) and RIPC in old | Administration of l-cysteine (20 mg/kg i.p.) thirty minutes prior to remote hind preconditioning stimulus, followed by isolation of heart after 24 h. Thereafter, 30 min of ischemia and 120 min of reperfusion to isolated heart |
| 8 | Group VIII | LC (40 mg/kg) and RIPC in old | Administration of l-cysteine (40 mg/kg i.p.) thirty minutes prior to remote hind preconditioning stimulus, followed by isolation of heart after 24 h. Thereafter, 30 min of ischemia and 120 min of reperfusion to isolated heart |
| 9 | Group IX | NaHS (20 µmol/kg) preconditioning in young | Administration of sodium hydrosulfide (20 µmol/kg i.p.) in young rats, followed by isolation of heart after 24 h. Thereafter, 30 min of ischemia and 120 min of reperfusion to isolated heart |
| 10 | Group X | NaHS (20 µmol/kg) preconditioning in old | Administration of sodium hydrosulfide (20 µmol/kg i.p.) in old rats, followed by isolation of heart after 24 h. Thereafter, 30 min of ischemia and 120 min of reperfusion to isolated heart |
| 11 | Group XI | YC-1 (1 mg/kg) in NaHS (20 µmol/kg) and RIPC in old | Treatment with YC-1 (1 mg/kg i.p.) thirty minutes prior to sodium hydrosulfide (20 µmol/kg i.p.) administration. The rest of protocol was same as group IV |
| 12 | Group XII | YC-1 (2 mg/kg) in NaHS (20 µmol/kg) and RIPC in old | Treatment with YC-1 (2 mg/kg i.p.) thirty minutes prior to sodium hydrosulfide (20 µmol/kg i.p.) administration. The rest of protocol was same as group IV |
| 13 | Group XIII | YC-1 (1 mg/kg) in LC (20 mg/kg) and RIPC in old | Treatment with YC-1 (1 mg/kg i.p.) thirty minutes prior to l-cysteine (20 mg/kg) administration. The rest of protocol was same as group VI |
| 14 | Group XIV | YC-1 (2 mg/kg) in LC (20 mg/kg) and RIPC in old | Treatment with YC-1 (2 mg/kg i.p.) thirty minutes prior to l-cysteine (20 mg/kg) administration. The rest of protocol was same as group VI |
| 15 | Group XV | DMSO in NaHS (20 µmol/kg) and RIPC in old | Treatment with DMSO, a solvent of YC-1, (2 ml/kg) thirty minutes prior to sodium hydrosulfide (20 µmol/kg) administration. The rest of protocol was same as group IV |
| 16 | Group XVI | DMSO in LC (20 mg/kg) and RIPC in old | Treatment with DMSO, a solvent of YC-1, (2 ml/kg) thirty minutes prior to l-cysteine (20 mg/kg). The rest of protocol was same as group VI |
RIPC, remote ischemic preconditioning; NaHS, sodium hydrosulfide; LC, l-cysteine.