PMID- 17450241
OWN - NLM
STAT- MEDLINE
DCOM- 20070612
LR  - 20181201
IS  - 1790-5427 (Print)
IS  - 1790-5427 (Linking)
VI  - 10
IP  - 1
DP  - 2007 Jan-Apr
TI  - The sodium-iodine symporter and the proton-pump inhibitors in - related to the 
      side effects of- the treatment of thyroid cancer with iodine-131.
PG  - 2-5
AB  - Iodine-131 ((131)I) administered to patients for imaging or treatment, 
      concentrates in the gastrointestinal tract, including the salivary glands, 
      stomach and bowel. In Nuclear Medicine practice this biological property of 
      iodine causes side effects when the therapeutic dose of (131)I is large. This 
      occurs during the treatment of patients with differentiated thyroid carcinoma 
      (DTC). During this clinical application, the dose of (131)I is higher than 3.7 
      GBq. Side effects of this treatment with respect to the stomach, include 
      gastritis as an inflammatory reaction to radiation, anorexia due to gastric 
      atrophy and rarely megaloblastic anemia due to lack of the endogenous factor. 
      Side effects can also include xerostomia. We have recently tried to prevent 
      gastric side effects by prescribing proton pump inhibitors (PPI) for patients 
      with DTC prior to treatment with (131)I. PPI block the excretion of hydrochloric 
      acid from the gastric mucosa and are utilized for the prevention and treatment of 
      gastritis, gastric ulcers and gastroesophageal reflux. Whole body scans before or 
      after the administration of PPI, showed that PPI do not interfere with the 
      biologic distribution of (131)I. These findings were not surprising. Recent 
      studies in animals and humans have shown that the accumulation and concentration 
      of iodine by the thyroid gland is the result of the selective action of sodium 
      iodine symporter (Na+I+symporter, NIS). Furthermore, it was shown that the 
      accumulation and concentration of (131)I in the parietal cells of the gastric 
      mucosa, the ductal cells of the salivary glands and the alveolar epithelial cells 
      of the mammary glands, is analogous to the biologic action of NIS in the thyroid 
      cells. The gastric mucosa accumulates iodine from the capillaries via the 
      extracellular/extravascular space and finally excretes it into the lumen of the 
      stomach, from where it is passively transferred into the bowel, where it is 
      partially reabsorbed to once again enter its metabolic cycle. On the contrary, as 
      it is now known, the PPI have an entirely different metabolic action, which is 
      unrelated to that of the NIS, although both mechanisms coexist in the parietal 
      cells of the gastric mucosa. Thus, during the application of (131)I for imaging 
      or for the treatment of DTC patients, except for the short period of time 
      immediately after the oral administration, when the radionuclide passes through 
      the stomach, the concentration of (131)I in the gastrointestinal tract is due to 
      its active accumulation and excretion by the gastric mucosa. PPI act only on the 
      hydrochloric acid secretion not affecting the biologic properties of iodine.
FAU - Sfakianakis, George
AU  - Sfakianakis G
FAU - Sfakianaki, Efrosyni
AU  - Sfakianaki E
LA  - eng
PT  - Editorial
PL  - Greece
TA  - Hell J Nucl Med
JT  - Hellenic journal of nuclear medicine
JID - 101257471
RN  - 0 (Iodine Radioisotopes)
RN  - 0 (Proton Pump Inhibitors)
RN  - 0 (Radiation-Protective Agents)
RN  - 0 (Radiopharmaceuticals)
RN  - 0 (Symporters)
RN  - 4XE5NDT4K1 (sodium-iodide symporter)
SB  - IM
MH  - Animals
MH  - Humans
MH  - Iodine Radioisotopes/*adverse effects/therapeutic use
MH  - Models, Biological
MH  - *Proton Pump Inhibitors
MH  - Radiation Injuries/etiology/*prevention & control
MH  - Radiation-Protective Agents/*administration & dosage
MH  - Radiopharmaceuticals/adverse effects/therapeutic use
MH  - Symporters/*antagonists & inhibitors
MH  - Thyroid Gland/drug effects/*metabolism/radiation effects
MH  - Thyroid Neoplasms/*metabolism/radiotherapy
EDAT- 2007/04/24 09:00
MHDA- 2007/06/15 09:00
CRDT- 2007/04/24 09:00
PHST- 2007/04/24 09:00 [pubmed]
PHST- 2007/06/15 09:00 [medline]
PHST- 2007/04/24 09:00 [entrez]
PST - ppublish
SO  - Hell J Nucl Med. 2007 Jan-Apr;10(1):2-5.