PSYC 181 Lecture Notes - Lecture 4: Astrocyte, Aspirin, Tight Junction
Document Summary
Drug distributions ion-trapping: aspirin: aspirin is a weak acid with pka of 3. 5 in stomach (ph 2-3), most aspirin not ionized in intestine (ph 5-6), more ionized. Once aspirin moved from stomach to blood, aspirin is trapped in in blood (ph 7. 4), most ionized (cid:271)lood (cid:894)does(cid:374)"t (cid:373)ove easily fro(cid:373) (cid:271)lood (cid:271)a(cid:272)k to sto(cid:373)a(cid:272)h(cid:895) Absorption: other factors: drug must be able to survive low ph, even if ionized and not very lipid soluble, digestive track has enormous surface area so may still get significant absorption. Astroglia: help comprise blood-brain barrier: sends processes which cover blood vessels. Inactivation usually by metabolism (biotransformation) to inactive forms (liver major site: elimination (metabolites or unchanged drug; kidney major site) But also lungs, sweat, saliva, feces, or milk. The study of the biochemical effects of drugs and their mechanism of action. Objective is identification of the primary actions of a drug.
