Akademik

1. The ability to endure or be less responsive to a stimulus, especially over a period of continued exposure. 2. The power of resisting the action of a poison or of taking a drug continuously or in large doses without injurious effects. [L. tolero, pp. -atus, to endure]

- acoustic t. the maximum sound pressure level that can be experienced without producing pain or permanent hearing threshold shift in a normal individual.

- cross t. the resistance to one or several effects of a compound as a result of t. developed to a pharmacologically similar compound.

- frustration t. the level of an individual's ability to withstand frustration without developing inadequate modes of response, such as “going to pieces” emotionally.

- high dose t. the induction of t. by exposure to high doses of antigen.

- immunologic t. lack of immune response to antigen. Theories of t. induction include clonal deletion and clonal anergy. In clonal deletion, the actual clone of cells is eliminated whereas in clonal anergy the cells are present but nonfunctional. SYN: immunotolerance, nonresponder t..

- immunologic high dose t. induction of t. by exposure to large amounts of protein antigens.

- impaired glucose t. excessive levels of blood glucose developing after a carbohydrate-rich meal or test dosage of glucose (usually 75 g). Not necessarily diagnostic of diabetes mellitus.

- individual t. t. to a drug that the person has never received before.

- nonresponder t. SYN: immunologic t..

- pain t. the greatest intensity of painful stimulation that an individual is able to tolerate.

- species t. the insensitivity to a particular drug exhibited by a particular species.

- split t. reaction to one (or more) antigen on a cell surface but no reaction to others. SYN: immune deviation.

- vibration t. the maximum vibratory or oscillatory movements that an individual can experience and bear without pain; the limit of t. is a function of amplitude and frequency of the vibration and varies with the direction of application.

tol·er·ance 'täl(-ə)-rən(t)s n

1) the capacity of the body to endure or become less responsive to a substance (as a drug) or a physiological insult esp. with repeated use or exposure <developed a \tolerance to painkillers>

2) the immunological state marked by unresponsiveness to a specific antigen

the reduction or loss of the normal response to a drug or other substance that usually provokes a reaction in the body. Drug tolerance may develop after taking a particular drug over a long period of time. In such cases increased doses are necessary to produce the desired effect. Some drugs that cause tolerance also cause dependence. See also glucose tolerance test, immunological tolerance, tachyphylaxis.