Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative disorder characterized by a central cholinergic deficit. Non-neuronal cholinergic changes are, however, described as well. Here we focused on possible changes in the activity of the plasma cholinesterases, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), in hospitalized AD patients. We analyzed plasma AChE and BChE activities with regards to age, gender, body mass index (BMI), cognitive functions, and ability to perform activities of daily living in AD patients in comparison to healthy subjects. We observed lower AChE activity and trend toward lower BChE activity in AD patients, which both correlated with low BMI. AD patients unable to perform basic activities of daily living (feeding, bathing, dressing, and grooming) showed reduced plasma AChE activities, while worse spatial orientation was linked to lower BChE activities. Three out of four AD patients with the lowest BChE activities died within one year. In conclusion, progressed AD was accompanied by lower plasma AChE activity and trend toward lower BChE activity, which correlated with BMI and deficits in different components of the AD.
- MeSH
- acetylcholinesterasa krev MeSH
- Alzheimerova nemoc patofyziologie terapie MeSH
- biochemická analýza krve MeSH
- butyrylcholinesterasa krev MeSH
- činnosti denního života * MeSH
- hospitalizace MeSH
- index tělesné hmotnosti * MeSH
- lidé středního věku MeSH
- lidé MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- změna polohy v prostoru fyziologie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Klíčová slova
- pH detekční metody, histochemické metody,
- MeSH
- acetylcholinesterasa * farmakologie fyziologie nedostatek škodlivé účinky MeSH
- biosenzitivní techniky metody normy přístrojové vybavení MeSH
- butyrylcholinesterasa * farmakologie fyziologie nedostatek škodlivé účinky MeSH
- chemické techniky analytické * využití MeSH
- cholinesterasové inhibitory MeSH
- cholinesterasy farmakologie fyziologie MeSH
- imunohistochemie metody normy přístrojové vybavení MeSH
- kolorimetrie metody normy přístrojové vybavení trendy MeSH
- lidé MeSH
- radiometrie metody normy přístrojové vybavení využití MeSH
- spektrofotometrie metody normy přístrojové vybavení MeSH
- titrace metody normy přístrojové vybavení MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Ellman's assay is the most commonly used method to measure cholinesterase activity. It is cheap, fast, and reliable, but it has limitations when used for biological samples. The problems arise from 5,5-dithiobis(2-nitrobenzoic acid) (DTNB), which is unstable, interacts with free sulfhydryl groups in the sample, and may affect cholinesterase activity. We report that DTNB is more stable in 0.09 M Hepes with 0.05 M sodium phosphate buffer than in 0.1M sodium phosphate buffer, thereby notably reducing background. Using enzyme-linked immunosorbent assay (ELISA) to enrich tissue homogenates for cholinesterase while depleting the sample of sulfhydryl groups eliminates unwanted interactions with DTNB, making it possible to measure low cholinesterase activity in biological samples. To eliminate possible interference of DTNB with enzyme hydrolysis, we introduce a modification of the standard Ellman's assay. First, thioesters are hydrolyzed by cholinesterase to produce thiocholine in the absence of DTNB. Then, the reaction is stopped by a cholinesterase inhibitor and the produced thiocholine is revealed by DTNB and quantified at 412 nm. Indeed, this modification of Ellman's method increases butyrylcholinesterase activity by 20 to 25%. Moreover, high stability of thiocholine enables separation of the two reactions of the Ellman's method into two successive steps that may be convenient for some applications.
- Publikační typ
- abstrakt z konference MeSH
