Evolution of aurosomes in rabbit synovial membrane.

Intra-articular injection of sodium aurothiomalate (Myochrysine) into rabbit knee joints produced lysomes (aurosomes) of a characteristic morphology in synovial intimal cells and subsynovial macrophages. Such lysosomes are distinct and different from other lysosomes and those seen after injection of sodium thiomalate. A study of the morphological events that occur after injection of gold salt shows that at first the aurosome contains electrondense granules but later membranous formations (myelinoid membranes) presenting as rod-like and curled structures develop. With electron probe x-ray analysis, gold, phosphorus, and traces of calcium were detected in the aurosome.