AUTORADIOGRAPHIC ANALYSIS OF THE UPTAKE OF [H-3] DOPAMINE, [H-3] ANGIOTENSIN-II AND [H-3] GAMMA-AMINOBUTYRIC-ACID BY THE CHICKEN THROMBOCYTE

The ability of chicken thrombocytes to take up and store transmitters of different categories, such as dopamine, angiotensin II and gamma aminobutyric acid (GABA), was examined by electron microscope autoradiography. Chicken thrombocytes selectively took up [H-3]dopamine, which was stored in large vacuoles with peripherally situated electron-dense granules. Exogenous [H-3]angiotensin II was also taken up by chicken thrombocytes. This accumulated in the same large vacuoles in which [H-3]dopamine was stored. No active uptake of exogenous [H-3]GABA was detected. The results indicate that chicken thrombocytes take up exogenous dopamine and angiotensin II which both appear to be stored in the same vacuoles, the amine storage organelles.