Age-related decrease in responsiveness to L-DOPA is not due to changes in dopamine receptor mRNAs or G protein mRNAs.
To clarify the cause of the age-related decrease in the responsiveness to L-DOPA seen in parkinsonian patients, we studied age-related changes in the mRNA levels of dopamine receptors (D1, D2) and of G proteins (Gs, Gi, Go) in 22 control human brains aged 50-105 years. Neither the mRNA levels of dopamine receptors or of the G proteins changed with age. Another factor in the receptor-G protein cascade, such as guanine nucleotide binding, may cause the age-related decrease in responsiveness.
Murata
M
M
Department of Neurology, School of Medicine, University of Tokyo, Japan.
Aihara
Y
Y
Yamanouchi
H
H
Yamada
S
S
Kanazawa
I
I
D000199:Actins / Q000096:biosynthesis; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000978:Antiparkinson Agents / Q000494:pharmacology*; D015152:Blotting, Northern; D001923:Brain Chemistry / Q000187:drug effects / Q000502:physiology; D005260:Female; D019204:GTP-Binding Proteins / Q000096:biosynthesis*; D006801:Humans; D066298:In Vitro Techniques; D007980:Levodopa / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000096:biosynthesis*; D011954:Receptors, Dopamine / Q000096:biosynthesis*; D017447:Receptors, Dopamine D1 / Q000096:biosynthesis; D017448:Receptors, Dopamine D2 / Q000096:biosynthesis
D000199:Actins; D000978:Antiparkinson Agents; D012333:RNA, Messenger; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D007980:Levodopa; D019204:GTP-Binding Proteins