Muscarinic receptor subtypes in hippocampus in Alzheimer's disease and mixed dementia type.
The relative proportion of super-high, high and low affinity agonist binding sites was measured in the hippocampus from individuals with dementia of the Alzheimer type (AD/SDAT), mixed (AD-MID) type and controls, using labelled quinuclidinyl benzilate ([3H]QNB) competing with unlabelled carbachol. A significant reduced number of [3H]QNB binding sites was obtained in dementia groups. A significant decrease in the proportion of super-high affinity agonist (V1) binding sites was found in the AD-MID group compared to controls while no change was found in the AD/SDAT group. The affinity constant (K1) for the V1 site was also significantly lower in the AD-MID group compared to controls.
D000368:Aged; D000544:Alzheimer Disease / Q000378:metabolism; D002217:Carbachol / Q000378:metabolism; D003704:Dementia / Q000378:metabolism*; D005260:Female; D006624:Hippocampus / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D008297:Male; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D011976:Receptors, Muscarinic / Q000032:analysis* / Q000378:metabolism
D011976:Receptors, Muscarinic; D011813:Quinuclidinyl Benzilate; D002217:Carbachol