Kienzl E, Riederer P, Jellinger K, Wesemann W
J Neural Transm. 1981;51(1-2):113-22. doi: 10.1007/BF01664009.
Crude membrane preparations from the frontal cortex of controls and parkinsonian patients were used to demonstrate affinity changes of the specific 3H-5-hydroxytryptamine (5-HT) binding sites. Two such sites were notable in controls, a finding consistent with earlier observations. In Parkinson's disease, both high- and low-affinity sites are significantly decreased. Additional experiments either with prolonged incubation times or pre-incubation with N-ethylmaleimide change the two affinities to a single high-affinity or low-affinity constant. The concept of transitional states of 5-HT receptors is discussed and seems to have important implications in the treatment of parkinsonism.
