title: Effect of Ca2+-antagonists on virally-induced cell-permeability changes.
abstract: Sendai virus-mediated permeability changes in cells are affected by extracellular Ca2+ or Mn2+ as follows: the lag period to onset of permeability changes is lengthened and the subsequent extent of leakage is reduced. Drugs that block Ca2+ action in excitable cells, such as verapamil and prenylamine, and drugs that inhibit the action of calmodulin, such as trifluoperazine and R24571, have an effect opposite to that of Ca2+: lag is shortened and extent of leakage is increased. The concentration at which either type of drug shows 50% of maximal effect is similar to the concentration at which 50% of binding by drug to calmodulin is achieved. It is concluded that calmodulin may be involved in protecting cells against virally-mediated membrane damage; alternatively the action of calmodulin-binding drugs may not be as specific as currently thought.
mesh_terms: D002118:Calcium / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002147:Calmodulin / Q000037:antagonists & inhibitors; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects*; D008345:Manganese / Q000494:pharmacology; D010222:Parainfluenza Virus 1, Human; D010253:Respirovirus Infections / Q000503:physiopathology*; D013329:Structure-Activity Relationship
chemical_list: D002121:Calcium Channel Blockers; D002147:Calmodulin; D008345:Manganese; D002118:Calcium