The differential effects of excitatory amino acids on uptake of 45CaCl2 by slices from mouse striatum.
Exposure to L-glutamate (10 mM) or 60 mM K+ for 1 min significantly stimulated the uptake of 45Ca2+ in slices from mouse striatum. Glutamate-induced stimulation was antagonized by 30 mM Mg2+ and by 5 or 10 mM L-glutamic acid diethyl ester, but not by 5 microM tetrodotoxin. Under these 1-min incubation conditions, neither kainate nor N-methyl-D,L-aspartate significantly affected the uptake of 45Ca2+ ion. By contrast, following preincubation for 10 min, glutamate and the conformationally restricted analogues, ibotenate, quisqualate, and kainate significantly inhibited the 60 mM K+-induced stimulation of the uptake of 45Ca2+. These effects of glutamate and kainate were not significantly affected by the presence of 1 mM Ca2+ in the preincubation medium. These results suggest that glutamate may activate a receptor directly linked to Ca2+ channels, whereas kainate may indirectly modulate the intracellular disposition of Ca2+.
D000042:Absorption; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002122:Calcium Chloride / Q000378:metabolism; D002132:Calcium Radioisotopes; D003342:Corpus Striatum / Q000378:metabolism*; D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates / Q000494:pharmacology*; D018698:Glutamic Acid; D066298:In Vitro Techniques; D007473:Ion Channels / Q000378:metabolism*; D007608:Kainic Acid / Q000494:pharmacology; D007811:Lanthanum / Q000378:metabolism / Q000494:pharmacology; D008297:Male; D051379:Mice
D002132:Calcium Radioisotopes; D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates; D007473:Ion Channels; C028521:lanthanum chloride; C011829:glutamic acid diethyl ester; D018698:Glutamic Acid; D007811:Lanthanum; D002122:Calcium Chloride; D007608:Kainic Acid; D002118:Calcium