Posted by Shawn. T. on June 29, 2004, at 19:44:19
In reply to Acetylcholinesterase vs. cholinesterase, posted by Questionmark on June 29, 2004, at 1:21:03
Acetylcholinesterase is a type of cholinesterase that is sometimes referred to as RBC (red blood cell) cholinesterase. Another major type of cholinesterase is butyrylcholinesterase, also known as serum cholinesterase or pseudocholinesterase. There are different isoforms (variants) for each type of cholinesterase. These enzymes catalyze the hydrolysis of esters of choline, but they may also exhibit other actions such as altering certain proteins. I've often seen people use the term cholinesterase to refer to acetylcholinesterase; one term is simply more specific than the other.
An inhibitor of acetylcholinesterase would act differently than an inhibitor of butyrylcholinesterase. I'm not especially familiar with the nature of these differences. Pfizer claims that drugs that selectively inhibit acetylcholinesterase have a better tolerability profile for Alzheimer's disease patients than drugs that inhibit both cholinesterases (see http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14751402 ). On the other hand, others have suggested that drugs that inhibit both cholinesterases may offer greater benefits, perhaps in a certain subgroup(s) of Alzheimer's patients (see http://www.alzheimer-insights.com/insights/vol7no4/vol7no4.htm and http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9403484 ). More research needs to be done to help us to better understand the different roles that these two enzymes play in the brain. There may be other types of endogenous cholinesterases in the body, but the two that I've mentioned are certainly the most important ones.
Shawn
poster:Shawn. T.
thread:361537
URL: http://www.dr-bob.org/babble/20040627/msgs/361763.html