title: Dipyridamole and RA-642 inhibit the production of superoxide anion and free radical damage to rat lens.
abstract: We studied the effects of dipyridamole and RA-642 on the production of superoxide anions and on oxygen radicals-induced lipid peroxidation in lens tissue homogenates from normal rats and rats given dipyridamole or RA-642 intraperitoneally. Superoxide production was evaluated by phenazine methosulphate (PMS)-induced nitroblue tetrazolium (NBT) reduction and lipid peroxidation by ferrous sulfate and ascorbic acid (FeAs)-induced malondialdehyde (MDA) production. Dipyridamole and RA-642 showed an inhibitory effect on both assays in the experiments with lens tissue homogenates from untreated or treated rats. The extent of inhibition, however, was significantly higher in pyrimidopyrimidinic-treated rats (range of inhibition at different times of incubation was 18% versus 23-57% for dipyridamole and 14% versus 73-80% for RA-642 in the assay of MDA production, and 10% versus 33-37% for dipyridamole and 2.5% versus 11-32% for RA-642 in the assay of NBT reduction). Concentrations of dipyridamole and RA-642 in lens tissue from treated animals could not be determined (less than 0.001 micrograms/mg of tissue). Although both compounds inhibited lipid peroxidation induced by oxygen free radicals, the mechanism of action might include the role of adenosine as a mediator.
authors.affiliation: Department of Pharmacology and Therapeutics, School of Medicine, University of Málaga, Spain.
authors.forename: J P
authors.initials: JP
authors.lastname: De la Cruz
authors.forename: A
authors.initials: A
authors.lastname: Sintas
authors.forename: A
authors.initials: A
authors.lastname: Moreno
authors.forename: J
authors.initials: J
authors.lastname: Garcia-Campos
authors.forename: F
authors.initials: F
authors.lastname: Sanchez de la Cuesta
mesh_terms: D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D004176:Dipyridamole / Q000494:pharmacology*; D005609:Free Radicals; D007908:Lens, Crystalline / Q000187:drug effects* / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D011743:Pyrimidines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013481:Superoxides / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D002316:Cardiotonic Agents; D005609:Free Radicals; D011743:Pyrimidines; D013481:Superoxides; C010650:RA 642; D004176:Dipyridamole