Evaluation of alveolo-capillary permeability in thyrotoxicosis using Tc-99m DTPA aerosol scintigraphy.

Abstract

Surfactant secreted from type II pneumocytes plays an important role in alveolo-capillary permeability. In thyrotoxicosis, high levels of T3 receptors detected at these cells might affect the alveolo-capillary permeability due to increased serum thyroid hormone levels. The results by CO-diffusion capacity measurement in thyrotoxicosis are conflicting. Changes in alveolo-capillary membrane permeability resulting from thyrotoxicosis are not well established yet. This prompted us to investigate the alveolo-capillary permeability in thyrotoxic patients in comparison with CO-diffusing capacity. For this aim twenty-two non-smoking thyrotoxic patients (before treatment) and fifteen healthy voluntary controls underwent 99mTc-DTPA aerosol scintigraphy. CO-diffusing and pulmonary function tests were performed in all subjects. After ventilation of radiotracer through a nebulizer for 15 minutes, 30 dynamic images (1 frame/minute) were taken from both lungs. ROI's were drawn over both lung areas, and the time-activity curves were generated. Then clearance half time (CT1/2) for radioaerosol was obtained. CT1/2 of thyrotoxic patients did not differ from that of the controls: 77.9 +/- 25.9 min vs. 79.4 +/- 22.3 min; p > 0.05. Similar result was found for CO-diffusion parameters. Also there was no significant correlation between CT1/2 and CO-diffusion parameters. We concluded that in patients with thyrotoxicosis, the alveolo-capillary permeability is unaffected. Further experimental research is needed to establish the possible effects of thyroid hormones on alveolo-capillary membrane.

• Authors: Aziz Gültekin, Mahmut Yüksel, Selva Mert, Sakir Berkarda
• Journal: Annals of nuclear medicine (Ann Nucl Med) Vol. 19 Issue 3 Pg. 193-6 (May 2005) ISSN: 0914-7187 [Print] Japan
• PMID: 15981671 (Publication Type: Clinical Trial, Controlled Clinical Trial, Journal Article)

Chemical References

• Aerosols
• Radiopharmaceuticals
• Technetium Tc 99m Pentetate

Topics

• Adolescent
• Adult
• Aerosols (pharmacokinetics)
• Aged
• Capillary Permeability
• Female
• Humans
• Male
• Middle Aged
• Pulmonary Alveoli (blood supply, diagnostic imaging, metabolism)
• Radionuclide Imaging
• Radiopharmaceuticals (pharmacokinetics)
• Technetium Tc 99m Pentetate (pharmacokinetics)
• Thyrotoxicosis (diagnostic imaging, metabolism)