NMDA-induced increase in [Ca2+]i and 45Ca2+ uptake in acutely dissociated brain cells derived from adult rats.
A preparation of acutely dissociated brain cells derived from adult (3-month-old) rat has been developed under conditions preserving the metabolic integrity of the cells and the function of N-methyl-D-aspartate (NMDA) receptors. The effects of glutamate and NMDA on [Ca2+]i measured with fluo3 and 45Ca2+ uptake have been studied on preparations derived from hippocampus and cerebral cortex. Glutamate (100 microM) and N-methyl-DL-aspartate (200 microM) increased [Ca2+]i by 26-12 nM and 23-9 nM after 90 s in cerebral cortex and hippocampus, and stimulated 45Ca2+ uptake about 16-10% in the same regions. The increases in [Ca2+]i and 45Ca2+ uptake were inhibited by 40% in the presence of 1 mM MgCl2 and by 90-50% in the presence of MK-801. The results indicate (a) that a large fraction of the [Ca2+]i response to glutamate in freshly dissociated brain cells from the adult rat involves NMDA receptors, (b) when compared with results in newborn rats, there is a substantial blunting of the [Ca2+]i increase in adult age.
Departamento de Biología Molecular, C.S.I.C. Universidad Autónoma de Madrid, Spain.
M
M
Villalba
A
A
Martínez-Serrano
C
C
Börner
P
P
Blanco
J
J
Satrústegui
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002132:Calcium Radioisotopes; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D066298:In Vitro Techniques; D008297:Male; D016202:N-Methylaspartate / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013050:Spectrometry, Fluorescence; D013997:Time Factors
D002132:Calcium Radioisotopes; D005971:Glutamates; D016194:Receptors, N-Methyl-D-Aspartate; D018698:Glutamic Acid; D016202:N-Methylaspartate; D000255:Adenosine Triphosphate; D002118:Calcium