Time-dependent inhibition of inositol-1,4,5-trisphosphate-5-phosphatase by calmidazolium chloride in rat GH3 cells.
The calmodulin inhibitor calmidazolium chloride inhibited the activity of soluble and particulate Ins(1,4,5)P3-5-phosphatase from GH3 cells, with an IC50 value of approximately 100 microM following a 10-min preincubation with the enzyme. The inhibition was time-dependent and could not be reversed by washing of the particulate fraction. It is concluded that although the inhibitory effect of calmidazolium chloride cannot be related per se to inhibition of calmodulin function, effects of this compound unrelated to actions upon calmodulin function may be found when concentrations that are only moderately supramaximal are used.
Fowler
C J
CJ
Astra Pain Control AB, Preclinical Research Department, Södertälje, Sweden.
Eriksson
A M
AM
D000818:Animals; D002147:Calmodulin / Q000037:antagonists & inhibitors; D002460:Cell Line; D007093:Imidazoles / Q000494:pharmacology*; D000072181:Inositol Polyphosphate 5-Phosphatases; D007700:Kinetics; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors*; D051381:Rats; D015398:Signal Transduction; D012995:Solubility
D002147:Calmodulin; D007093:Imidazoles; C031938:calmidazolium; D010744:Phosphoric Monoester Hydrolases; D000072181:Inositol Polyphosphate 5-Phosphatases