Effect of guanidino-propionic acid on lymphocyte proliferation.

The 'uremic toxin', guanidino propionic acid (GPA), which was detected in uremic serum in correlation with BUN level, modified the mitogenic response of normal lymphocytes to phytohemagglutinin (PHA). Mild modifications can be detected in the concentrations which are found in uremic patients. Other guanidino compounds which have been detected in uremic sera, such as guanidino succinic acid (GSA), guanidino butyric acid (GBA) and guanidino acetic acid (GAA), show similar inhibitory pathways. It is suggested that guanidino compounds contribute to the immunological disturbances in uremia. The complexity of their action on lymphocyte mitogenic response is probably the cause of the conflicting results which have been reported in the literature.