In vitro interaction of heavy metals with ouabain receptors in rat brain microsomes.
This study investigates the influence of heavy metals on ouabain-binding in presence of thiol (sulfhydryl) compounds. The data on in vitro effects of mercury (Hg), lead (Pb) and cadmium (Cd) showed significant inhibition of 3H-ouabain binding to microsomal membrane in a concentration-dependent manner. Maximum inhibition of 3H-ouabain binding was observed at 1 microM for Hg and 100 microM each for Pb and Cd. Preincubation with monothiol (L-cysteine or glutathione) or dithiol (dithiothreitol) protected inhibition of 3H-ouabain binding to the membranes by Hg or Pb. Dithiol but not monothiols partially protected Cd-inhibition. The present data confirm that the heavy metals interact with ouabain receptors in a manner similar to SH-blocking agents and protection of metal-inhibited 3H-ouabain binding by thiol compounds is metal specific.
Chetty
C S
CS
Division of Natural Science, Selma University, Alabama 36701.
Stewart
T C
TC
Cooper
A
A
Rajanna
B
B
Rajanna
S
S
D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002104:Cadmium / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004347:Drug Interactions; D007854:Lead / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008297:Male; D008628:Mercury / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008861:Microsomes / Q000187:drug effects / Q000378:metabolism; D010042:Ouabain / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011955:Receptors, Drug / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase; D013438:Sulfhydryl Compounds / Q000494:pharmacology*
D011955:Receptors, Drug; D013438:Sulfhydryl Compounds; C028996:cardiac glycoside receptors; D002104:Cadmium; D007854:Lead; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase; D008628:Mercury