Mechanisms of Toxicity
Start with the big picture
Toxicodynamics explains how the magnitude of a toxic effect relates to dose, duration of exposure, and individual susceptibility. Some xenobiotics are converted by Phase I CYP450 enzymes into reactive intermediates that bind proteins or DNA. Other mechanisms include oxidative stress and loss of glutathione defenses, mitochondrial dysfunction, calcium overload, and excessive glutamate signaling. Toxicants may also inhibit enzymes, block ion channels, or disturb receptor activity. The topic further covers immune-mediated injury, effects on development and endocrine signaling, epigenetic changes, DNA damage, lysosomal membrane rupture, bioaccumulation, and interactions between toxicants. Together, these mechanisms provide a framework for understanding how chemical exposures can disrupt cellular function and lead to injury.
What you'll learn
- Relate toxic effect magnitude to dose, exposure duration, and target susceptibility.
- Explain how CYP450-mediated bioactivation can generate reactive intermediates.
- Describe cellular injury associated with oxidative stress, glutathione depletion, and mitochondrial dysfunction.
- Identify how toxicants can disrupt enzymes, ion channels, receptors, and neuronal signaling.
- Recognize immune, developmental, endocrine, genetic, and interaction-related mechanisms of toxicity.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
