| Bioactivity | Iopanoic acid is an inhibitor of 5'-Deiodinase and also an iodinated contrast medium. | ||||||||||||
| Target | 5'-Deiodinase | ||||||||||||
| Invitro | The thyrotropin-releasing-hormone (TRH)-induced thyrotropin (TSH) release from the pituitary fragments is inhibited by 3,5,3'-triiodothyronin (T3) (10-7 M), by triiodothyroacetic acid (10-7 to 10-7 M), and by high concentrations of iodide (10-4 or 10-5 M). Iopanoic acid has no significant effect at the concentrations tested[2]. | ||||||||||||
| In Vivo | Iopanoic acid (IOP) administration to pregnant rats during days 18 and 19 postconception does not modify litter size (controls: 11.8±0.5 fetusesldam, Iopanoic acid-treated: 11.6±0.6 fetusesldam) or body weight at day 20 (controls: 3.27±0.12 g, Iopanoic acid-treated: 3.42±0.20 g). Iopanoic acid treatment produces a significant blockage of 5'-Deiodinase (5'D) activity in interscapular brown adipose tissue (IBAT) and brain; in contrast, liver 5'D is not modified. 3,5,3'-triiodothyronin (T3) content is similar in IBAT and slightly increased in brain and liver nuclei of Iopanoic acid-treated fetuses when compare with control fetuses at day 20 (p<0.05). However, when administered to adult rats, Iopanoic acid produces a significant reduction in IBAT nuclear T3 content and plasma T3 concentration. Iopanoic acid inhibition of IBAT 5'D activity in fetuses at term is as effective as at day 20[1]. | ||||||||||||
| Name | Iopanoic acid | ||||||||||||
| CAS | 96-83-3 | ||||||||||||
| Formula | C11H12I3NO2 | ||||||||||||
| Molar Mass | 570.93 | ||||||||||||
| Appearance | Solid | ||||||||||||
| Transport | Room temperature in continental US; may vary elsewhere. | ||||||||||||
| Storage |
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| Reference | [1]. Tuca A, et al. Inhibition of iodothyronine 5'-deiodinase by iopanoic acid does not block nuclear T3 accumulation during rat fetal development. Pediatr Res. 1994 Jan;35(1):91-5. [2]. Szabolcs I, et al. Effects of triiodothyronine, triiodothyroacetic acid, iopanoic acid and iodide on the thyrotropin-releasing hormone-induced thyrotropin release from superfused rat pituitary fragments. Acta Endocrinol (Copenh). 1991 Oct;125(4):427-34. |