The xenobiotico, to carry out its action, must come into contact with our body through ingestion, contact or inhalation. Once inside the body it must undergo a series of steps before reaching the target site.
In the figure above the passages that the xenobiotic must undergo are reported. On the left, in particular, the various passages that serve the toxic to illustrate their dangerous action in the organism are illustrated. On the right side, instead, the passages that go to contrast the dangerous activity of the xenobiotic are reported.
Xenobiotics exploit the same distribution and elimination mechanisms applied to drugs.
The processes listed on the left of the image are:
- ABSORPTION
- ORAL (drug intoxication, poisoning, suicides, food plants);
- INHALATION (gas intoxication, smoke, crack, fine dust PM10);
- PERCUTANEOUS (insecticides, nerve gas, toxic lipid solubility, skin condition, vehicle);
- DISTRIBUTION (the toxic substance is distributed using the same method as drugs taking into account the permeability of capillaries, possible barriers and binding to plasma proteins);
- REABSORPTION
- toxification
The processes listed on the right are:
- PREHISTORY DISPOSAL (first hepatic passage) ;
- DISTRIBUTION OUTSIDE THE TARGET;
- EXTRACTION (elimination via the renal route);
- DETOXIFICATION ( Phase 1 association with functional groups and Phase 2 conjugation for the elimination of the toxic)
It is not always said that with the elimination process the toxic molecule is neutralized; indeed, sometimes the molecule that forms with the elimination processes is much more dangerous than the starting one. A good balance between the various left and right processes determines the actual concentration of xenobiotic at the level of the target site.
The initial amount of xenobiotic coming into contact with the organism is not the same as that which reaches the target site, precisely because the substance can first undergo different metabolic processes.
