Lymph heart scintigraphy in the toad

To our knowledge, there are no reports on the use of radionuclide labeled agents to image the lymphatic system of anuran amphibia. Lymphoscintigraphy was performed in 18 toads Bufo marinus L, after the injection of Tc-99m-serum albumin within the ventral lymph sac. Images were obtained with a rectilinear scanner immediately after tracer administration. Scintigrams were digitalized and densitometric profiles were obtained. One or more lymph hearts were demonstrated on all 18 scans. Scintigrams showed the four lymph hearts functioning simultaneously in only 17% of the toads. Lymphoscintigraphy with Tc-99m serum albumin is useful to study the movement of lymph from the lymph sacs or to study the function of lymph hearts in amphibia.