The accumulation of an aryloxylkylamidine (501C) and 5-hydroxytryptamine in human polymorphonuclear leucocytes: a...

The uptake of anilino-N-2-m-chlorophenoxypropylacetamidine (501C) and 5-hydroxytryptamine (5-HT), in human polymorphonuclear leucocytes (PMN) was investigated by quantitative ultrastructural autoradiography. The major concentration of both drugs was in the cytoplasmic granules, 71.5 +/- 6.8% for [3H] 501C, and 68.75 +/- 6.1% for [3H]5-HT. Lesser quantities of both drugs were associated with the nucleus; 18.1 +/- 4.8% for [3H] 501C and 23.0 +/- 4.2% for [3H] 5-HT. Only small amounts of activity were recorded at other sites. The data suggests that there may be common binding sites for 501C and 5-HT in PMN. Furthermore the concentration of 501C in PMN granules may also account for the damaging effect of high concentrations of the drug on PMN.