title: Serum Anticholinergic Activity as an Index of Anticholinergic Activity Load in Alzheimer's Disease.
abstract: We reported a procedure of serum anticholinergic activity (SAA) measurement and the reliability and reproducibility of the receptor binding assay, and we also described the usefulness of SAA measurement reflecting the anticholinergic activity (AA) in the central nervous system (CNS). According to the results of a 10 times repeated measurement of standard atropine binding, the relative error was between -5.5 and +3.7%, and we considered that measurement of SAA in our studies is accurate and validated. Downregulation of acetylcholine activates inflammation in both CNS and peripheral tissue, which causes AA in both sites. Therefore, changes of AA in the CNS link with SAA in the peripheral system even if a substance having AA does not penetrate through the blood-brain barrier. Then we redescribe issues that require attention in the measurement of SAA. It is generally defined that any SAA greater than the detection limit of a quantitative atropine equivalent level (≥1.95 nM in our study) is positive. According to previous studies, SAA is considered to be positive when its atropine equivalent is ≥1.95 nM and undetectable when this is <1.95 nM. Nevertheless, as a low SAA can act as AA in the CNS, we should assume that SAA might also be positive if its marker concentration is between 0 and 1.95 nM. In addition, SAA should be measured around 11 a.m. or somewhat later because of the diurnal rhythm of cortisol in humans.
authors.affiliation: Department of Pharmaceutical Therapeutics, Division of Clinical Pharmacy, School of Pharmacy, Showa University, Yokohama, Japan.
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Hachisu
authors.forename: Kimiko
authors.initials: K
authors.lastname: Konishi
authors.forename: Misa
authors.initials: M
authors.lastname: Hosoi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Tani
authors.forename: Hiroi
authors.initials: H
authors.lastname: Tomioka
authors.forename: Yuka
authors.initials: Y
authors.lastname: Kitajima
authors.forename: Atsuko
authors.initials: A
authors.lastname: Inamoto
authors.forename: Akihito
authors.initials: A
authors.lastname: Hirata
authors.forename: Taishi
authors.initials: T
authors.lastname: Koganemaru
authors.forename: Akisa
authors.initials: A
authors.lastname: Tomita
authors.forename: Norihisa
authors.initials: N
authors.lastname: Akashi
authors.forename: Koji
authors.initials: K
authors.lastname: Hori
mesh_terms: D000544:Alzheimer Disease / Q000097:blood* / Q000188:drug therapy*; D018680:Cholinergic Antagonists / Q000097:blood* / Q000627:therapeutic use*; D006801:Humans
chemical_list: D018680:Cholinergic Antagonists