Different target sizes of the voltage-dependent Ca2+ channel and the [3H]nitrendipine binding site in rat brain.
High energy irradiation of frozen rat frontal cortex was used to determine the molecular target sizes of the [3H]nitrendipine binding site (93,500 +/- 9,700 daltons and of the voltage-dependent Ca2+ channel (340,500 +/- 34,000 daltons) determined as the K+-induced 45Ca2+ uptake into synaptosomes. The conclusion that could be drawn from the target size analysis was that 45Ca2+ flux occurs via a structure of molecular weight very different from that of the dihydropyridine binding site. Furthermore, it was found that [3H]nitrendipine binding to synaptosomes was not influenced by depolarization with K+.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels; D002132:Calcium Radioisotopes; D066298:In Vitro Techniques; D007473:Ion Channels / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D008970:Molecular Weight; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011978:Receptors, Nicotinic / Q000378:metabolism*
D015220:Calcium Channels; D002132:Calcium Radioisotopes; D007473:Ion Channels; D011978:Receptors, Nicotinic; D011188:Potassium; D002118:Calcium