[An effect of aluminum on hemesynthesis--special reference to erythrocyte uroporphyrinogen--1--Synthetase and protoporphyrin]

In order to evaluate an inhibitory effect of Al on haem synthesis, erythrocyte uroporphyrinogen-1-synthetase (RBC-Uro-S) activity and erythrocyte level of protoporphyrin (RBC-protoporph) were measured and compared with RBC-Al in 22 patients on maintenance hemodialysis. RBC-Uro-S activity was varied from 38 to 83 nM/ml RBC/hr 37 degrees C (54.18 +/- 12.42 nM/ml RBC/hr 37 degrees C) and a slight elevation could be found no more than in two cases. On the other hand, RBC-protoporph levels showed to be significantly elevated in many cases such as 8 cases out of 22 (36.4%). (normal subjects: 63.25 +/- 27.61 micrograms/dl RBC, HD patients: 90.0 +/- 28.35 micrograms/dl RBC). This study failed to confirm a significant negative correlation between RBC-Al and RBC-Uro-S activity, but a positive significant correlation could be found between RBC-Al and protoporphyrin levels. However we could confirm a negative correlation neither between RBC-Al and Hb values nor between RBC-Uro-S activity and Hb values. Therefore we concluded that Al-intoxication in the patients on long term hemodialysis had a definite inhibitory effect on heme synthesis, but it was by no means a major factor in pathogenesis of anemia associated with chronic dialysis.