Dose-dependent

Dose-dependent refers to the changes in effect on an organism caused by differing levels of exposure (or doses) to a stressor (usually a chemical) after a certain exposure time. This is a fundamental concept in toxicology and pharmacology, where it is often referred to as the dose-response relationship.

Overview

A dose-response relationship is the relationship between the quantity of a substance and the effect it has on an organism. In pharmacology, it is used to understand how different doses of a drug affect the body, while in toxicology it is used to understand the toxic effects of chemicals.

Dose-Dependent Effects

Dose-dependent effects can be divided into three categories: threshold effects, non-threshold effects, and hormesis.

Threshold Effects

Threshold effects are those that occur above a certain dose but not below. This is the most common type of dose-response relationship.

Non-Threshold Effects

Non-threshold effects are those that occur at any dose, no matter how small. This type of dose-response relationship is less common and is often associated with very toxic substances.

Hormesis

Hormesis is a dose-response relationship where a low dose of a substance has a beneficial effect, but a high dose has a harmful effect. This is a controversial concept in toxicology and pharmacology.

Factors Influencing Dose-Dependent Effects

Several factors can influence dose-dependent effects, including the individual's genetics, age, sex, and overall health. Other factors include the duration and frequency of exposure, and the presence of other chemicals.

See Also

• Pharmacology
• Toxicology
• Dose (biochemistry)
• Dose (radiation)

References

Dose-dependent Resources
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