Review
General | Preconditioning specific |
---|---|
• Robust cerebroprotection | • Two phased: early and delayed |
• The interval between preconditioning and ischemia determines the fate | • Early tolerance starts in minutes, delayed tolerance not usually before 24 h |
• Ischemic tolerance is transient | • After early phase, but before delayed phase no tolerance is achieved |
• Ischemic tolerance can be induced by a variety of stimuli | • Early phase is short-lasting, delayed phase longer, up to 1 week |
• Transient ischemic attacks confer ischemic tolerance in humans | • Preconditioning preserves cortical/penumbral tissue in focal ischemia models |
I. Nomenclature
PC
Ischemic preconditioning (IPC)
IT
Ischemia-tolerant phenotype (Figure 1)
Latent cerebroprotective phenotype
Cerebroprotection or protection
II. Two phases of IT
III. Models for IT
Global-Global
Four-vessel occlusion
Two-vessel occlusion and hypotension
Two-vessel occlusion in gerbils
Two-vessel occlusion in mice
Focal-Focal
Transient focal-permanent focal
Transient focal-transient focal
Focal-Global
Cross-Tolerance
Protection* (%) | Follow-up** | Ref. | |
---|---|---|---|
Focal-focal, in rats
| |||
15 min MCAO - 72 h later pMCAO | 41 | 24 h | [47] |
10 min MCAO - 72 h later 60 min tMCAO | 44 | 7 d | [59] |
3 min tMCAO - 72 h later 60 min tMCAO | 35 | 24 h | [57] |
Focal-focal, in mice
| |||
3 × 5 min tMCAO - 30 min later pMCAO | 23 | 24 h | [50] |
3 × 5 min tMCAO - 30 min later 60 min tMCAO | 32 | 24 h | [49] |
15 min MCAO - 72 h later 45 min tMCAO | 70 | 24 h | [58] |
LPS
| |||
LPS 0.5 mg/kg - 72 h later 60 min tMCAO in rats | 35 | 24 h | [98] |
Hypoxia
| |||
11% oxygen for 2 h - 48 h later 90 min tMCAO in mice | 46-64 | 24 h | [66] |
Anestesia
| |||
Isoflurane 1.4% for 3 h - 0, 12, and 24 h later pMCAO in rats | 31-35 | 4 d | [113] |
Halothane 1.2% for 3 h - 24 h later pMCAO in rats | 35 | 4 d | [113] |
Spreading depression
| |||
KCl application - 4 days later 120 min tMCAO in rats | 43 | 4 d | [191] |
Hyperbaric oxygen
| |||
100% oxygen for 1 h, 5 days-24 h later pMCAO in mice | 27 | 24 h | [69] |