Uptake and secretion of technetium pertechnetate by the rat parotid gland

Abstract

1. 1. The ability of acinar cells of the rat parotid gland to transport technetium pertechnetate ( 99mTcO − 4) was examined. 2. 2. After intravenous injection, 99mTcO − 4 was rapidly detected in parotid saliva. 3. 3. There was an excellent correlation between saliva and plasma 99mTcO − 4 levels. The saliva to plasma ratio was always < 1, consistent with the inability of rat parotid gland duct cells to concentrate the anion. 4. 4. Output of 99mTcO − 4 by the parotid gland closely mimicked fluctuations in parotid saliva flow rate. 5. 5. In vitro, enzymatically dispersed parotid acinar cells accumulated 99mTcO − 4 from the incubation medium in a biphasic manner. This uptake was partially blocked by 10 −4 M NaI. 6. 6. Cells which had accumulated 99mTcO − 4showed increased radionuclide efflux after exposure to 10 −5 M carbachol.