Toxicology LEC

• Golden era of medieval toxicology

  Middle Ages
• Types of Antagonism


  o Receptor antagonism

  o Chemical antagonism- inactivation

  o Dispositional antagonism

  o Functional antagonism
• 1 + 1= 0 or <1

  Antagonism
• 1 + 0= 2

  Potentiation
• 1+ 1= 3

  Synergistic
• 1 + 1= 2

  Additive
• Quantal Dose-Response Relationship


  o Effective dose (ED)

  o Lethal dose (LD)

  o Threshold dose
• magnitude of the response


  related to the dose
• Response


  is due to the chemical administered.
• Threshold dose


  Lowest dose at which a particular effect is observed.
• Lethal dose (LD)


  Dose required to cause death in a certain percentage of individuals.
• Effective dose (ED)


  Dose required to produce a specific effect in a certain percentage of individuals.
• Quantal Dose-Response Relationship


  Relationship between dose and the proportion of a population affected.
• Graded Dose-Response Relationship


  Relationship between dose and response in an individual.
• Chemical allergy

  Hypersensitivity
• poison or puison

  a drink
• TOXIC SUBSTANCES:

  •Xenobiotics

  o Pharmaceuticals

  o Pesticides
• TOXIC SUBSTANCES:

  • Toxin

  Aflatoxin
• Allergic reactions


  Immune responses to a substance.
• Adverse effects


  Harmful effects of a substance.
• What are some specialized roles within toxicology?

  Mechanistic Toxicologist, Hazard Assessment Toxicologist, Regulatory Toxicologist, Environmental Toxicologist, Computational Toxicologist.
• How can toxic substances be classified?

  By physical state, chemical state, general stability or reactivity, ability to cause significant toxicity, biochemical mechanisms of actions, descriptive categories.
• Toxicant


  Any toxic substance.
• Xenobiotic


  Substances foreign to an organism's biochemistry.
• Toxin


  A poison produced by living organisms.
• Toxicogenomics


  Studies how genes respond to toxicant exposure.
• Regulatory Toxicology


  Involves the development and implementation of regulations to protect public health from toxic exposures.
• Occupational Toxicology


  Examines the impact of workplace exposures to toxic substances.
• Environmental Toxicology


  Studies the effects of toxicants on the environment and ecosystems.
• Forensic Toxicology


  Involves the analysis of toxic substances in legal contexts.
• Clinical Toxicology


  focuses on diagnosing and treating poisonings in clinical settings.
• Mechanistic Toxicology


  Investigates the mechanisms by which toxicants produce their effects.
• Descriptive Toxicology


  Describes the nature of toxicity and how it manifests.
• Give 5 Branches of Toxicology

  Descriptive Toxicology

  Mechanistic Toxicology

  Clinical Toxicology

  Forensic Toxicology

  Environmental Toxicology
• Toxicokinetic


  refers to the absorption, distribution, metabolism, and excretion of the toxicant.
• Toxicodynamic


  refers to the effects of a toxicant on the body
• Poisonous


  refers to substances that are harmful when ingested or absorbed
• Venomous


  refers to organisms that inject toxins through a bite or sting.
• Overdose


  refers to excessive consumption of a substance.
• Poison


  refers to a substance that causes harm