Possible Interaction: Cd2+ and Calcium Supplement

“These Ca2+ signals were inhibited by nifedipine, Cd2+ , U73122, xestospongin C and ryanodine, suggesting contributions from both Ca2+ influx through voltage dependent L-type Ca2+ channels plus Ca2+ release from intracellular stores mediated by IP3 receptors and ryanodine receptors.”

“ Cd2+ (100 μm), which nearly eliminates L-type, N-type, P/Q-type, and R-type Ca currents while sparing approximately one-half the T-type current, prevents Ca changes during and after hyperpolarizations to ECl.”

“Currents, … Ca2+ or Ba2+ and blocked … 0.4 mM Cd2+ , were activated by depolarizations positive to −50 mV and peaked at −23 mV. At −23 mV they reached 1.1 ± ….1 nA in the presence of 5 mM Ca2+ and 1.6 ± 0.1 nA in 5 mM Ba2+.”

“Similarly, the P-type Ca2+ channel antagonist ω-agatoxin IVA (ω-Aga IVA) (0.05 μM) and the inorganic Ca2+ channel blocker Cd2+ (0.2 mM) inhibited the outflow of both transmitters, while Ni2+ (0.1 mM) was without significant effect.”

“In the presence of Cd2+ (100 µM), which inhibits the L-type Ca2+ current, strophanthidin had negligible effects on current suggesting that Ca2+ influx via Na-Ca exchange during depolarization does not account for the increase of s.r.”

“Conductances showed the characteristics of an L-type Ca2+ channel: divalent cation selectivity (PBa/PNa approximately equal to 30), blockage of Na+ conductance by micromolar Ca2+, and blockage of the Ca2+ channel by D890 and by Cd2+.”

“However, Cd2+ and Ni2+ (10 microM each) blocked the Ca current by ca.”

“frequency depended … amount of Ca2+ (greater than … blocked by Cd2+ , or by Ca2+ at about 10 microM. The quantal content of end‐plate potentials was usually reduced in the presence … control values after removal of La3+ by 'washing' with solution containing EDTA, once a raised m.e.p.p.”

“Among the coexisting cations, the removal of Cd2+ was decreased by Ca2+ and Mg2+, while K+ had limited effect on the removal of Cd2+.”

“In the differentiated zone of roots growing in Cd2+ solution, calcium addition stimulated DNA synthesis but the intensity of this process was lower than in control (water).”