Eosinophilic leucocytes and phospholipase B of rat tissues.

The correlation between the eosinophilic leucocyte population and the phospholipase B activity of rat tissues has been tested with isolated cell preparations from intestine, lung, blood, bone marrow and spleen containing eosinophils in varying proportions and with pure eosinophil fractions separated by centrifugation on discontinuous metrizoate and metrizamide gradients. A uniform value of activity per cell was found in all these tissues extending previous histochemical and biochemical evidence that the eosinophil is the carrier cell for the phospholipase B to all major sites of distribution. The enzyme marker approach has been used for estimating the normal eosinophil population of rat organs and show the distribution pattern of the eosinophils in peripheral organs in the wake of increased production and release from the marrow.