Effects of Synthetic Iodolipids on Thyroid Function “In Vitro”: Possible Role in Thyroid Regulation
The inhibitory effects of iodine on the thyroid are mediated by an iodine organic intermediate (see review, 1), whose chemical nature is not known. Although thyroid hormones have been proposed to be such intermediates, their role is still controversial (see ref. 2 for discussion). It is known that, in addition to thyroid hormones, the gland is capable of synthesizing iodolipids (see review, 3), another type of organic iodocompounds. We have recently shown that iodinated free fatty acids comprise most of the iodolipids (4). The results obtained with different inhibitors of arachidonic acid metabolism suggested that iodinated derivatives of arachidonic acid may be a component of iodinated free fatty acids. Moreover, recent data from our laboratory has shown that in calf thyroid slides incubated with 125I, the incorporation of radioiodine into 15-iodo14-hydroxy- and 15-hydroxy-14-iodo-eicosatrienoic acid (I-OH-A) and the corresponding lactones was observed (to be published). Boeynaems and Hubbard (5) have also shown that rat thyroid produces the acid 5-iodo-6hydroxy-eicosatrienoic 8,11,14 delta lactone (IL-δ). In a previous publication, we have demonstrated that a semi-purified preparation of iodoarachidonate inhibits in vitro different thyroid parameters (6). We have also shown that studies with pure preparations of I-OH-A and another derivative with an iodine atom in position 6 (IL-δ).
KeywordsArachidonic Acid Thyroid Hormone Iodine Uptake Iodine Atom Arachidonic Acid Metabolism
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- 2.Pisarev MA. J Endocrinol Invest, in press.Google Scholar
- 3.Pisarev MA, Burton G, Busse Grawitz P, et al. Ninth International Thyroid Congress, 1985.Google Scholar
- 4.Chazenbalk GD, Pisarev MA, Juvenal GJ, et al. Acta Endocrinol (Kbh) 108: 72, 1985.Google Scholar
- 6.Chazenbalk GD, Pisarev MA, Krawiec L, et al. Acta Physiol Pharmacol Latinoamer. 34: 367, 1984.Google Scholar
- 7.Pisarev MA and Aiello LO. Acta Endocrinol (Kbh) 82: 298, 1976.Google Scholar
- 8.Kleiman de Pisarev DL, Pisarev MA, and Juvenal GJ. Acta Endocrinol (Kbh) 89: 316, 1978.Google Scholar
- 9.Kleiman de Pisarev DL, Pisarev MA, and Spaulding SW 104: 634, 1979.: 298, 1976.Google Scholar