Toxicology 03 + 04 – ADME (absorption, distribution, metabolism and
excretion)
Membrane passing
Passive transport (cost no energy) (higher to lower);
• Simple diffusion (non-specific, without help of
membrane proteins)
• Facilitated diffusion (specific, with help of
membrane proteins)
Active transport (costs energy) (lower to higher);
• Making use of transporter proteins (specific)
• There are antiporters and symporters
• Direct (primary) active transport; process itself costs energy
• Indirect (secondary) active transport; recovery process costs energy
Endocytosis;
• Fagocytose; “eten” van de cel, vaak partikels → non specific
• Pinocytosis; “drinken” van de cel, vaak opgeloste eiwitten →
non-specific
• Receptor mediated endocytosis → specific mediated
endocytosis. See picture.
Exocytosis; inverted endocytosis
Toxicokinetcs; fate (lot) of a compound after exposure
Absorption (opname)
• Dermal
• Oral intake
o Portal vein; oxygen poor blood, nutrient full blood
• Inhalator intake
o Very fast, because the blood in the
(longblaasjes) removes continue the oxygen. So,
the oxygen in the lungs in continue taken up
again.
Intake; is the dose
• Oral intake; passing the GI track without absorption
• Inhalator intake; exhaling of non-absorbed gasses
Uptake; is the absorption
Total absorption = f (absorption efficiency) x intake
Example for total absorption; flung = 30% fGI track=6%
Smoking; 0,3 x (25x0,16); 0,16 microgram per cigarette, 25 cigarettes per day.
Distribution (verdeling)
Concentration = Dose / volume
excretion)
Membrane passing
Passive transport (cost no energy) (higher to lower);
• Simple diffusion (non-specific, without help of
membrane proteins)
• Facilitated diffusion (specific, with help of
membrane proteins)
Active transport (costs energy) (lower to higher);
• Making use of transporter proteins (specific)
• There are antiporters and symporters
• Direct (primary) active transport; process itself costs energy
• Indirect (secondary) active transport; recovery process costs energy
Endocytosis;
• Fagocytose; “eten” van de cel, vaak partikels → non specific
• Pinocytosis; “drinken” van de cel, vaak opgeloste eiwitten →
non-specific
• Receptor mediated endocytosis → specific mediated
endocytosis. See picture.
Exocytosis; inverted endocytosis
Toxicokinetcs; fate (lot) of a compound after exposure
Absorption (opname)
• Dermal
• Oral intake
o Portal vein; oxygen poor blood, nutrient full blood
• Inhalator intake
o Very fast, because the blood in the
(longblaasjes) removes continue the oxygen. So,
the oxygen in the lungs in continue taken up
again.
Intake; is the dose
• Oral intake; passing the GI track without absorption
• Inhalator intake; exhaling of non-absorbed gasses
Uptake; is the absorption
Total absorption = f (absorption efficiency) x intake
Example for total absorption; flung = 30% fGI track=6%
Smoking; 0,3 x (25x0,16); 0,16 microgram per cigarette, 25 cigarettes per day.
Distribution (verdeling)
Concentration = Dose / volume
