KINETICS OF NEUTROPHILIC GRANULOCYTES IN THE BLOOD OF RATS

Abstract

ABSTRACT The kinetics of neutrophilic granulocytes in the blood of rats were investigated using in vivo 3 H‐TdR labelling and autoradiography. The radioactive precursor was administered by single injection, repeated injections at 5 hr intervals and continuous infusion. The appearance of labelled granulocytes in the blood and in the sputum was recorded up to 120 hr after tracer application. In contrast to results after a single injection of 3 H‐TdR, complete labelling of the blood granulocyte pool was achieved when the DNA precursor was given by continuous infusion or four repeated injections at 5 hr intervals. In the latter experiments, an exponential replacement of unlabelled blood granulocytes by labelled granulocytes could be demonstrated, the mean intravascular half‐life being 5·7 hr. This figure is in good agreement with values obtained by isotopic techniques in other mammalian species.