biodistribúció

Biodistribución is a term used in pharmacology and toxicology to describe the process by which a substance, such as a drug or toxin, is distributed throughout the body of an organism. It refers to the movement of the substance from its site of administration or absorption to various tissues and organs. Understanding biodistribution is crucial for determining the efficacy and safety of pharmaceutical compounds and for assessing the potential harm of toxic agents.

The biodistribution of a substance is influenced by a variety of factors. These include the physicochemical properties of the substance itself, such as its solubility, molecular size, and lipophilicity. The route of administration also plays a significant role; for example, intravenous administration leads to rapid and widespread distribution, while oral administration involves absorption from the gastrointestinal tract and first-pass metabolism in the liver, which can alter the distribution pattern. Blood flow to different organs is another key determinant, with highly perfused organs like the liver, kidneys, and brain typically receiving higher concentrations of the substance initially. Furthermore, interactions with biological barriers, such as the blood-brain barrier and placental barrier, can limit or facilitate distribution to specific compartments. The presence of specific transporters or receptors in target tissues can also influence where a substance accumulates.

Studies of biodistribution are typically conducted using various techniques, including imaging methods like PET (Positron Emission Tomography) and SPECT (Single-Photon Emission Computed Tomography), as well as direct measurement of the substance in biological samples (blood, urine, tissues) over time. These studies help to map out the concentration of the substance in different parts of the body and understand its pharmacokinetic profile. This information is essential for optimizing drug dosage, predicting potential side effects, and understanding mechanisms of toxicity.