[The effect of dihydropyridines on the strontium and calcium content in frog muscle]. / Vliianie digidropiridinov na soderzhanie strontsiia i kal'tsiia v mushtse liagushki.

2,6-Dimethyl-3,5-dimethoxycarbonyl-4-(O-difluromethoxyphenyl)-1,4- dihydropyridine (ryodipine) (2 x 10(-4) M) significantly blocks the resting Sr++ uptake in sartorius and iliofibularis muscles of Rana temporaria without changes in Ca++ and Mg++ content. Dihydropyridine CGP (2.10(-4) M) increased both [Sp++] and [Ca++] (mumol/g dr. w.) by about 20 and 13%, respectively, as compared with paired control muscles, whereas [Mg++] remained unaffected. The [Sr++] changes are interpreted as specific dihydropyridine-effect on the Ca(++)-channels in the muscle membrane.

[Effect of dihydropyridines on cation transport across the skeletal muscle membrane in the frog]. / Vliianie digidropiridinov na transport kationov cherez membranu skeletnoi myshtsy liagushki.

2,6-Dimethyl-3,5-dimethoxycarbonyl-4-(o-difluromethoxyphenyl)- 1,4-dihydropyridine (ryodipine) blocks Ca-channels in phasic muscle fibres from ileofibularis and semitendinosus muscle of Rana esculenta. Ryodipine and some other newly synthesized dihydropyridines (10(-7)-10(-4) M) exerted a slight, if any, effect on the steady-state of potassium chord conductance in isotonic K+-sulfate solution. The effluxes of potassium and rubidium from the sartorius muscle of Rana temporaria also remained unchanged after addition of 2 x 10(-4) M ryodipine. Thus, the nonspecific dihydropyridine effect on ion transport seems to be poorly expressed.

[Use of antioxidants to prevent damage during acute ischemia and reperfusion of the kidneys]. / Primenenie antioksidantov dlia profilaktiki povrezhdenii pri ostroi ishemii i reperfuzii pochek.

Prophylactic injection of the natural antioxidant alpha-tocopherol and synthetic antioxidants ionol, diludin and 6-mercurascan prevented the development of lesions during acute renal ischemia and subsequent reperfusion. Ionol proved more effective on intraperitoneal injection than on intragastric route of administration. It has been demonstrated that antiischemic effect of ionol is related to its ability to exhibit the process of lipid peroxidation.

[Regulation of peroxidation of mitochondrial membrane lipids initiated by Fe2+ ions by antoxidants of the 1,4-dihydropyridine series in experiments in vitro]. / Reguliatsiia initsiiruemogo ionami Fe2+ perekisnogo okisleniia lipidov mitokhondrial'nykh membran v opytakh in vitro antioksidantami 1,4-digidropiridinovogo riada

Effect of antioxidants on the rate of free radical peroxidation was studied in mitochondria in presence of Fe2+. For this purpose derivatives of 1,4-dihydroxypyridine, their heteroaromatic analogues, NAD-H+ and butyl hydroxytoluene (35 substances) were tested in the system by chemoluminescence. Several 1,4-dihydroxypyridine derivatives were found to be effective reagents in the system and could be compared by the activity with the recognized synthetic antioxidant butyl hydroxytoluene.