Popis: |
When we speak about absorption of macromolecular substances we must take into consideration the barriers of the gastrointestinal tract which hinder their uptake and transportation into the lymphatics and the blood. These barriers can be differentiated into morphological and functional barriers. The enzymes of the gastrointestinal tract may destroy macromolecular substances before they can be absorbed, and this enzymatic activity acts as a functional barrier. Intrinsic properties of the macromolecules including solubility, lipophilicity and charge, may also impede the absorption and can be regarded as a functional barrier. The morphological barrier is represented by the anatomical structures of the intestinal mucosa. |