59Fe labelling of rabbit erythrocytes as a continuous source for iron metabolism studies

The study of iron metabolism in human phagocytes requires a continuous source of 59Fe-labelled erythrocytes with high specific activity. Previously, rats and mice have been used for this purpose, but only limited amounts of blood can be obtained and the animals are (often) sacrificed during the experiment. This paper describes the development of a rabbit model for use as a continuous source of highly labelled erythrocytes as an alternative to mice and rats. A chinchilla rabbit was serially injected with 59Fe citrate to maintain a level of labelling of 12 x 10(5) cpm/ml of blood. During the 42-month use of the chinchilla rabbit, a total of 190 MBq was injected and a total of 277 ml blood was withdrawn. During the whole period, the health of the animal was not affected and no important changes were found in any of the haematological parameters studied. The protocol was successfully applied with a second rabbit with the same results. Our model provides a simple continuous source of highly labelled erythrocytes, minimizing the number of animals otherwise needed for this type of experiment.