Posted by SLS on February 9, 2003, at 20:40:45
In reply to Re: Is there an updated list? » SLS, posted by Dave1 on February 8, 2003, at 15:34:22
Hi Dave.
Sorry I didn't see your post earlier.
First - what is a receptor?
A receptor is a site upon which specific chemicals (known as ligands) bind. The receptor usually functions to trigger biological events when it is stimulated. For instance, a serotonin receptor is a protein found on the surface of certain neurons. Serotonin (5-HT) is a neurotransmitter (ligand) that, when attached to its receptor, stimulates it and causes the receiving neuron to send a message.
A ligand can either stimulate a receptor or block that receptor from being stimulated by other ligands:
AGONIST: A ligand that attaches to and stimulates a receptor is an agonist of that receptor.
ANTAGONIST: A ligand that attaches to a receptor without stimulating it, thereby preventing stimulatory ligands to gain access to it is an antagonist of that receptor.
PARTIAL AGONIST: A ligand that attaches to and stimulates a receptor to a degree less than that of a full agonist.
There are often multiple receptor subtypes that bind the same neurotransmitter. 5-HT1a is a subtype of serotonin receptor. Not only does it bind natural serotonin, but also specific drugs. Often, a drug will bind to one subtype and not another. Gepirone binds to 5-HT1a receptors but not 5-HT2 receptors. With Serzone, the reverse is true.
I hope this was helpful.
- Scott
poster:SLS
thread:139984
URL: http://www.dr-bob.org/babble/20030208/msgs/140364.html