Wolff-Chaikoff effect

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Wolff-Chai·koff block

(vulf chī'kof),
obstruction of the organic binding of iodine and its incorporation into hormone, caused by large doses of iodine; usually transient, but in large doses in susceptible people, the effect can be prolonged and cause iodine myxedema.
[Louis Wolff; Israel Chaikoff]
Farlex Partner Medical Dictionary © Farlex 2012

Wolff-Chaikoff effect

Endocrinology An acute adaptive response to high doses of iodine–↑ intracellular iodide blocks the organic-binding and coupling reactions in the thyroid, functionally turning off the thyroid; the WCE used to prepare the thyroid for surgery. See Hyperthyroidism.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.


Louis, U.S. cardiologist, 1898-1972.
Wolff-Chaikoff block - blocking of the organic binding of iodine and its incorporation into hormone caused by large doses of iodine. Synonym(s): Wolff-Chaikoff effect
Wolff-Chaikoff effect - Synonym(s): Wolff-Chaikoff block
Wolff-Parkinson-White syndrome - an electrocardiographic pattern sometimes associated with paroxysmal tachycardia. Synonym(s): preexcitation syndrome
Medical Eponyms © Farlex 2012
References in periodicals archive ?
The major actions of iodide on thyroid function are inhibition of thyroid hormone release from the thyroid gland and a transient decrease in thyroid hormone synthesis (the acute Wolff-Chaikoff effect) [4].
Initially, increased intrathyroidal iodine concentration decreases thyroid hormone synthesis by inhibiting TPO, thus preventing organification; this is known as the Wolff-Chaikoff effect [2-4].
Due to the compensatory mechanisms, such as the Wolff-Chaikoff effect, the changes in T3 and T4 levels following an increase in iodide intake are minimal and usually transient in nature [26-28].
Keywords: Amiodarone, Thyroid disorder, Wolff-Chaikoff effect, Hypothyroidism, thyrotoxicosis.
He asserted that the Wolff-Chaikoff interpretation, which became known as the "Wolff-Chaikoff Effect," was absolutely wrong, though it became the focus of attention for the entire health-care industry.
Many thyroidologists consider an iodine intake greater than 1 to 2 mg to be potentially harmful, citing the Wolff-Chaikoff effect (39) and an increase in TSH (thyroid stimulating hormone) concentration with intakes greater than this amount.
"The Wolff-Chaikoff effect: Crying wolf?" The Original Internist, 2005; 12(3):112-118.
This fictitious phenomenon became known as the Wolff-Chaikoff effect. (12)
Following a well-designed protocol, they reported, "It is concluded that the rapid decrease in [T.sub.4] secretion induced by iodine is not the result of an acute sustained inhibition of [T.sub.4] synthesis (the Wolff-Chaikoff effect), but rather results from an abrupt decrease in the fractional rate of thyroid [T.sub.4] release." Therefore, in hyperthyroidism, iodine/iodide in Lugol at a daily dose of 90 mg induced a physiological trend toward normalization of thyroid function, a beneficial effect, not the fictitious W-C effect as proposed by Wolff and Chaikoff.
This fictitious phenomenon became known as the Wolff-Chaikoff effect. (5) Because these law-abiding rats refused to become hypothyroid and instead followed their normal physiological response to the iodide load, they were unjustly accused of escaping from the law of the Wolff-Chaikoff effect.
Wolff, (5) coauthor of the world famous Wolff-Chaikoff effect published in 1948.
During the year Stanley published his "extension of the Wolff-Chaikoff Effect to man," he co-authored a paper with Astwood on using goitrogens to manage patients with Graves' disease as an alternative to using inorganic iodine/iodide.