L-glutamate binding sites of normal and atrophic human cerebellum.
The binding kinetics, pharmacologic properties, ontogeny and localization of L-glutamate binding sites were studied in membrane preparations and sections of normal and olivopontocerebellar atrophy (OPCA) human cerebellum. One binding component was found with a Kd value in the order of 150 x 10(-9) M. No significant changes of Kd values were observed with age, whereas the highest Bmax value was observed at the age of 1 year. L-Aspartate, ibotenate, quisqualate and L-homocysteic acid were potent inhibitors of L-[3H]glutamate binding. Quantitative densitometric measurements indicated the presence of L-glutamate sites in both the molecular and granule cell layer. In OPCA cerebella a very significant decrease of L-[3H]glutamate specific binding (Bmax) was observed, whereas Kd values were found unchanged. The pharmacologic properties of L-[3H]glutamate binding sites of OPCA cerebellar tissues were similar to those of normal cerebellum. [3H]quinuclidinyl benzylate binding, expressed in fmol/mg protein, did not show significant differences between normal and OPCA cerebella.
Tsiotos
P
P
Department of Physiology, School of Medicine, University of Patras, Greece.
Plaitakis
A
A
Mitsacos
A
A
Voukelatou
G
G
Michalodimitrakis
M
M
Kouvelas
E D
ED
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism* / Q000473:pathology; D001667:Binding, Competitive; D002531:Cerebellum / Q000254:growth & development / Q000378:metabolism* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007700:Kinetics; D008875:Middle Aged; D010069:Oxadiazoles / Q000378:metabolism; D016318:Quisqualic Acid; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter / Q000378:metabolism*
D005971:Glutamates; D010069:Oxadiazoles; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter; D018698:Glutamic Acid; D016318:Quisqualic Acid