title: Effects of calcium on phthalocyanine sensitized photohemolysis.
abstract: Influence of divalent Ca2+ ions in sulphonated chlorophthalocyanine (ClAlPcS2) induced photohemolysis in rabbit red blood cells has been investigated. Loading of excess Ca2+ to ClAlPcS2 sensitized RBC suspension enhanced hemolysis in a concentration dependent manner. Protein kinase C (PKC) inhibitor chlorpromazine and cation chelator EDTA reduced Ca2+ enhanced photohemolysis. Photohemolysis increased with calcium channel blockers diltiazem and nifidipine. Enhancement in photohemolysis by Ca2+ ions can arise either by its ability to liberate Fe2+ bound to phosphatidylserine or by stimulation of PKC. Inability of calcium channel blockers to prevent Ca2+ influx following photodynamic treatment of red blood cells suggest nonspecific leakage rather than involvement of Ca2+ channels in erythrocytes.
authors.affiliation: Institute of Nuclear Medicine & Allied Sciences, Delhi, India.
authors.forename: R
authors.initials: R
authors.lastname: Varshney
authors.forename: V
authors.initials: V
authors.lastname: Jain
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002746:Chlorpromazine / Q000494:pharmacology; D004533:Egtazic Acid; D004912:Erythrocytes / Q000187:drug effects / Q000528:radiation effects; D006461:Hemolysis / Q000187:drug effects* / Q000528:radiation effects; D007211:Indoles / Q000494:pharmacology*; D054833:Isoindoles; D007700:Kinetics; D008027:Light; D017319:Photosensitizing Agents / Q000494:pharmacology*; D011817:Rabbits
chemical_list: D002121:Calcium Channel Blockers; D007211:Indoles; D054833:Isoindoles; D017319:Photosensitizing Agents; D004533:Egtazic Acid; D002118:Calcium; D002746:Chlorpromazine; C013647:phthalocyanine