RES History

Join Communication Committee member Samson Kosemani as he looks back into the great science hidden in the RES archives.

The Reticuloendothelial-Blocking Effect of Rare Earth Metals in Rats

It had established that rare earth metals impact the reticuloendothelial system (RES) by aggravating the Shwartzman phenomenon as well as the effect of shock yet nothing was known about their significance on the granulopectic activity of the RES. To address this, George Lazar in 1972 investigated the influence of rare earth metal chlorides on RES activity and on reticuloendothelial stimulation by zymosan, triolein, and Bacillus Calmette Guerin (BCG).

The first observation by Lazar was that the granulopectic activity of the RES was significantly depressed within 24 hr by gadolinium chloride. The same was observed for the chlorides of lanthanum, cerium, neodymium, holmium, and ytterbium in spite of zymosan or triolein treatment. Secondly, Lazar noted similar RES-blocking action when the experimental setup was left for an extended period of time.

In summary, Lazar opined that RES depression is due to saturation of the reticuloendothelial cells by colloids and to a marked reduction in the ingestion of additional colloidal particles by phagocytes evident from literature but said in his work that further experiments were being performed to elucidate the mechanism of action of the rare earth metals.