Bismuth uptake in rat testicular macrophages: a follow-up observation suggesting that bismuth alters interactions between testicular macrophages and Leydig cells.

Recent studies suggest that bismuth accumulates in Leydig cells. In addition, a reduced level of serum testosterone and a statistically significant reduction of Leydig cells have been observed. It was therefore hypothesized that Bi has a direct toxic effect on rat Leydig cells. We have now developed a method for double labeling of bismuth and ED-2 (a marker for testicular macrophages). The present data demonstrate that the heavily bismuth-loaded cells in rat testis, originally interpreted as being Leydig cells, are bismuth-loaded macrophages. Consequently, our data suggest a modified hypothesis regarding bismuth-induced interactions between testicular macrophages and Leydig cells.