The Pineal Gland and Melatonin
George H. Gass, Harold M. Kaplan in Handbook of Endocrinology, 2020
Female hamsters that were placed in short photoperiod or blinded also had reduced plasma levels of T4 and FTI.362,363 This reduction in circulating T4 and FTI was prevented by pinealectomy as well.362 Circulating TSH was reported to be depressed by short photoperiod.363 Short photoperiod (1L/23D) was found to attenuate the thyroid weight increase observed in animals treated with the goitrogen thiourea.364 TRH content of the hypothalamus was found to be increased by blinding, an effect that was again prevented by pinealectomy.365 The interpretation of this work was that an intact pineal gland had an inhibitory influence on TRH release in hamsters, an interpretation shared by several laboratories.292,358,359
Roots and Tubers
Christopher Cumo in Ancestral Diets and Nutrition, 2020
As noted, processing is necessary to minimize toxins. Even meticulous efforts cannot remove all cyanide. The body uses essential amino acids methionine and cystine to detoxify the remainder. Both being essential for growth, a 2008 paper implicated their metabolism for detoxification in stunting children.92 Moreover, a by-product of cyanide detoxification is the anion thiocyanate (SCN−), which hinders the thyroid gland’s storage and use of the mineral iodine and which is known as a goitrogen. Without iodine, the thyroid—in a condition known as hypothyroidism—cannot manufacture the hormones thyroxine and triiodothyronine necessary to regulate cells’ production of proteins, including enzymes that help control metabolism. The thyroid also makes the hormone calcitonin to regulate calcium in the blood. The gland is part of a cascade that begins with the hypothalamus, a region in the brain central to emotions, sleep, appetite, thirst, and libido. The hypothalamus regulates the thyroid by signaling the pituitary gland to secrete thyroid-stimulating hormone (TSH). The pituitary calibrates TSH by sensing the amounts of thyroxine and triiodothyronine in blood.
Introduction
Robert Fried, Richard M. Carlton in Flaxseed, 2023
Thiocyanate can act as a goitrogen, meaning that it blocks the uptake of iodine by the thyroid gland. When the diet is overly rich in goitrogens, the thyroid gland swells to trap as much iodine as possible forming a goiter or lump in the neck. The Council notes, however, that there is no evidence that consuming flaxseed produces symptoms of goiter. In fact, goiter is not a health problem where iodine intake is adequate, and it is rare in North America. Goiter occurs mainly in Asia and Africa, and in 96% of cases, it is due to iodine deficiency or consumption of cassava and not to the overconsumption of known plant goitrogens. (12)
Arecoline inhibits pineal–testis function in experimentally induced hypothyroid rats
Published in Archives of Physiology and Biochemistry, 2020
Indraneel Saha, Suman Bhusan Chakraborty, Aniruddha Chatterjee, Debajyoti Pradhan, Urmi Chatterji, B. R. Maiti
PTU, a goitrogen, is a potent antithyroid drug which inhibits both synthesis of thyroid hormones and conversion of thyroxine (T4) to its active form, triiodothyronine (T3), in peripheral tissues (Yang and Gordon 1997). Hypothyroid activity of PTU is well documented in hyperthyroid patients (Melmed et al. 2011) as well as in animal species rats, mice, house musk, shrew (Takeuchi et al. 2006, Norris and Carr 2013). PTU is known to act by inhibition of tetraiodothyronin-5-deiodinase type I and type 2, of which type 2 is predominant in human osterblasts (Morimura et al. 2005). Additionally, D2 rather D1, is responsible for the maintenance of T3 level in shrews unlike in human and rodents liver and cerebral cortex in sickness and starvation (Takeuchi et al. 2006).
Related Knowledge Centers
- Propylthiouracil
- Sulfadimethoxine
- Thiocyanate
- Thyroid Hormones
- Pituitary Gland
- Thyroid-Stimulating Hormone
- Goitre
- Potassium Perchlorate
- Iopanoic Acid
- Goitrin