Effects of serine, cysteine and aspartic acid protease inhibitors and calpain inhibitor 1 on calpain activity measured in situ in RPT suspensions
| Treatment | Calpain activity |
|---|---|
| % of control | |
| Control | 100 ± 0a |
| E64d (0.05 mM) | 106 ± 6a |
| Leupeptin (0.5 mM) | 98 ± 4a |
| Pepstatin A (0.2 mM) | 97 ± 3a |
| 3,4-Dichloroisocoumarin (0.2 mM) | 89 ± 5b |
| N-p-tosyl-l-lysine chloromethyl ketone (0.1 mM) | 82 ± 4b |
| Calpain inhibitor 1 (1 mM) | 38 ± 4d |
| PD150606 (100 μM) | 66 ± 6c |
The protease inhibitors, calpain inhibitor 1 or PD150606 were added after a 15-min preincubation period, and calpain activity was determined 30 min later. See the text for a detailed description of the calpain assay.
Values are mean ± S.E.M. (n = 3).
Values with different superscripts are significantly different from one another (P < .05).