Table 2.
PDE5 inhibitors in cognition. EEG, electroencephalogram, i.m. intramuscular, i.p. intraperitoneal, ORT object recognition test, p.o. per os, s.c. subcutaneously.
| PDE5 inhibitor | Doses | Route | Test | Animals | Behavioral Results | Reference |
|---|---|---|---|---|---|---|
| Zaprinast | 3 or 10 mg/kg | i.p. | ORT (4h interval) | 3 months old Tryon–Maze–Bright rats | 10 mg/kg improved memory consolidation | Prickaerts et al. 1997 [69] |
| Zaprinast | 0.5, 1 or 2 mg/kg | i.p. | Elevate plus-maze and passive avoidance task | 3 and 20–22 months old Swiss mice | All doses improved memory in aged animals; 1 and 2 mg/kg improved memory in young animals | Patil et al. 2004 [77] |
| Zaprinast | 0.3 mg/kg | s.c. | ORT (2h interval) | 3 and 12 months old Wistar rats | Pro-cognitive action only for the young animals. No effect in older animals. | Domek-Łopacińska and Strosznajder 2008 [70] |
| Sildenafil | 1, 3, 10 or 30 mg/kg | i.p. | Active avoidance learning | 2 months old Swiss mice | 3 mg/kg improved performance | Baratti and Boccia 1999 [76] |
| Sildenafil | 0.25, 0.5 or 1 mg/kg | i.p. | Elevate plus-maze and passive avoidance task | 3 and 20–22 months old Swiss mice | All doses improved memory in aged animals-0.5 and 1 mg/kg improved memory in young animals | Patil et al. 2004 [77] |
| Sildenafil | 1, 3 or 10 mg/kg | p.o. | ORT (24h interval) | 4 months old Wistar rats | 3 and 10 mg/kg improved memory consolidation | Prickaerts et al. 2005 [73] |
| Sildenafil | 0.3, 1 or 3 mg/kg | p.o. | ORT (24h interval) | 6 months old Swiss mice | 1 mg/kg improved memory consolidation | Rutten et al. 2005 [74] |
| Sildenafil | 1, 3, 10 or 20 mg/kg | i.p. | Passive avoidance task | 2 and 12-month old Wistar rats | No memory enhancing effect | Shafiei et al. 2006 [78] |
| Sildenafil | 0.3, 1 or 3 mg/kg | i.m. | Object retrieval task | Cynomolgus macaque | 1 and 3 mg/kg improved memory performance | Rutten et al. 2008 [84] |
| Sildenafil | 3mg/kg daily for 3 weeks | i.p. | ORT and MWM | 26–30 months old C57Bl/6J mice | Improved performance in both tests | Palmeri et al. 2013 [79] |
| Vardenafil | 0.5 mg/kg | p.o. | 14-unit T-maze | 3,17, and 24-month-old rats | Improved spatial memory retention | Devan et al. 2014 [85] |
| Vardenafil | 0.3 mg/kg | i.p. | Object location test (24h interval) | 4–5 months old mice | Improved spatial memory acquisition and early consolidation | Argyrousi et al. 2019 [87] |
| Tadalafil | 15 mg/kg | p.o. | MWM | 3-month-old J20 transgenic mice | Improved memory performance | Garcia-Barroso et al. 2013 [86] |