Abstract
To study the selectivity of calmodulin antagonists it was assumed that they should inhibit noradrenaline (NA)- and K+-induced contractions similarly without an accompanying inhibition of45Ca uptake. Therefore, in isolated rat aorta the effects of W-7, calmidazolium and trifluoperazine on contraction and45uptake elicited by K+and NA were investigated. Calmidazolium (10-5-10-4mol/l) elicited an incomplete inhibition of K+- and NA-induced contraction and45Ca uptake. Trifluoperazine inhibited the NA-induced contractions at lower concentrations (10-6-10-4mol/l). The K+- and NA-induced45Ca uptake was blocked by trifluoperazine (10-5mol/l). W-7 (10-5-10-4mol/l) inhibited the K+- and NA-induced45Ca uptake. In conclusion, the results indicate that calmidazolium and trifluoperazine are hardly useful as calmodulin antagonists because of their additional properties, whereas W-7 seems to be the least unspecific of the calmodulin antagonists studies.
| Original language | English |
|---|---|
| Pages (from-to) | 317-326 |
| Number of pages | 10 |
| Journal | Pharmacology |
| Volume | 39 |
| Issue number | 5 |
| Publication status | Published - 22-Oct-1989 |
Keywords
- 45Ca uptake
- Calmodulin antagonists
- contraction
- rat aorta
- calmidazolium
- calmodulin
- n (6 aminohexyl) 5 chloro 1 naphthalenesulfonamide
- noradrenalin
- potassium chloride
- radioisotope
- trifluoperazine
- animal cell
- aorta
- article
- calcium transport
- drug concentration
- male
- nonhuman
- priority journal
- rat
- smooth muscle contraction