Interrelationship of Pyrrole and Globin Metabolism in β‐Thalassaemia *

Abstract

Detailed metabolic studies in a case of β‐thalassaemia intermedia following 14C‐2‐glycine administration demonstrate some of the interrelationships of pyrrole pigments and haemoglobins, and some secondary effects of a β‐thalassaemia mutation. Marked increase in the early‐labelled fraction of faecal bile pigment was confirmed; labelling rose to a maximum at 5 days, in advance of the haem peak, and was approximately three times greater than maximum haem labelling. Urinary coproporphyrins were increased in quantity, thus allowing complete serial determinations of radioactivity, which was at its maximum within 24 hours. The urine also contained a brown pigment, probably a dipyrrole, which had a labelling pattern resembling that of the urinary coproporphyrins, with maximum activity in the first sample. It is suggested that the ‘dipyrrole’may arise by early destruction of redundant haem associated with α‐chains. At all times, haemoglobin F was more highly labelled than haemoglobin A in both the haem and the globin moieties. Mean cell survival estimated graphically from the various curves was approximately 32 days. Haem/globin ratios were similar to those reported previously in normal subjects and in thalassaemia.

The Pattern of Disordered Haemoglobin Synthesis in Homozygous and Heterozygous β‐Thalassaemia*

“…The finding of haem attached to at least some of the excess a-chains supports the view (Kreimer-Birnbaum and Bannerman, 1968) that the excess of dipyrolles which is found in thalassaemic urine may reflect breakdown of excess @-chain with haem attached. This mechanism may also account for much of the excess 'early-labelled bile' fraction which characterizes the ineffective erythroyoiesis of p-thalassaemia.…”

Erythrocyte Content of Free Protoporphyrin in Thalassaemic Syndromes

“…The EP values varied from 19 to 110 and from 22 to 75 ,«g/100 ml in the two groups, respectively. Finally, Kreimer-Birnbaum and Bannerman [7] in a study on the interrelationship of pyrrole and globin metabolism in /Mhalassaemia quote that the EP content of a patient with heterozygous /Mhalassaemia varied from 35 to 85 ,«g with a mean value of 52.5 /yg/100 ml of erythrocytes.…”