The morphology and atomic composition of aurosomes produced by sodium aurothiomalate in human monocytes.

Aurosomes were found in monocytes (from the peripheral blood of man) incubated with sodium aurothiomalate. In electron micrographs the aurosome presents as a single-membrane-bound lysosomal body with an electron-lucent or medium density matrix in which lie electron-dense filamentous (straight or curled), rod-like and lamellar profiles studded with particles and granules. Similar deposits did not develop in monocytes incubated with sodium thiomalate but myelinoid membranes and rod-like structures presumably derived from them were seen in the lysosomes of these cells. The aurosomes (and their characteristic electron-dense contents) produced in the monocytes in vitro were morphologically indistinguishable from those known to occur in various tissues of man and experimental animals treated with soluble goldsalts. The atomic composition of the aurosomes produced in vitro appears to be similar to that produced in vivo for in both instances Au, P and S can be demonstrated in the aurosome. It is concluded that the aurosomes produced in our experimental model is an accurate copy of that found in in vivo situations.