Evaluation of alveolo-capillary permeability in thyrotoxicosis using Tc-99m DTPA aerosol scintigraphy.
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.
Department of Nuclear Medicine, Trakya University Medical Faculty, Edirne, Turkey.
Aziz
A
Gültekin
Mahmut
M
Yüksel
Selva
S
Mert
Sakir
S
Berkarda
D000293:Adolescent; D000328:Adult; D000336:Aerosols / Q000493:pharmacokinetics; D000368:Aged; D002199:Capillary Permeability; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011650:Pulmonary Alveoli / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000378:metabolism; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D016284:Technetium Tc 99m Pentetate / Q000493:pharmacokinetics*; D013971:Thyrotoxicosis / Q000000981:diagnostic imaging* / Q000378:metabolism*
D000336:Aerosols; D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate