The types of receptors that bind to drugs seems like male-female relationships..
1. Ion channel ..CRUSH .. very fast emotions, first look.. but fast they discovered the truth ..they separate. 2. G-protein..someone searching for a relationship. they can be specific or non specific in their selection because they value the relationship more, therefore it may last but not that long. They miss (up-regulation) or feel down (down-regulation) and their response sometimes are huge which reflect their massive emotions but less mind work.
3. Tyrosine kinase or enzyme linked.. those are mature, they know exactly who they bind and their response last longer as they know how to response in first minutes or after several years ..sorry I mean days.
These are some collection of Pharmacology lectures and notes. All the credit to my friends in Pharmacology department in National University of Malaysia (UKM). I added my own lectures, updated, modified some and kept some untouched.