In these studies the effects of ingested arsenic (As(+5)) on hepatic heme biosynthetic capability and hemoprotein function in adult male rats were investigated. Animals exposed for 6 weeks to 0, 20, 40, or 85 ppm sodium arsenate in the drinking water suffered depression of hepatic delta-aminolevulinic acid (ALA) synthetase and heme synthetase (ferrochelatase) activities, with maximal decreases ...

To the Editor: A 50‐year‐old man presented with recurrent episodes of bullae, erosions, and crust on sun‐exposed areas for 1 year. Lesions healed with scarring and hyperpigmentation. The skin lesions were aggravated after sun exposure. The patient had a 30‐year alcohol abuse (100–200 ml/day) history. Family heredity history was unremarkable. Physical examination revealed multiple erosions with ...

Lead acetate was administered to adult New Zealand White rabbits in their drinking water. Their mean blood lead level rose to 4.5 mumol/l within a week and then remained relatively constant. The rabbits developed a marked coproporphyrinuria. Plasma levels of coproporphyrin increased but not in proportion to the urine excretion. Thus the renal clearance of coproporphyrin rose from a mean of 1.8 ...

EDITOR,—The porphyrias are a group of rare inherited disorders caused by specific enzymatic defects of the haem biosynthetic pathway. Congenital erythropoietic porphyria (CEP) is an extremely rare autosomal recessively inherited disorder of the haem synthesis pathway first described by Günther in 1911. Clinical symptoms are caused by a homozygous defect of the enzyme uroporphyrinogen III syntha...

1 . Thin-layer chromatography of porphyrin methyl esters provides a useful and rapid technique for resolving mixtures of porphyrins from biological samples. 2. Application of this technique to urinary, faecal and hepatic porphyrins from patients with symptomatic porphyria revealed five porphyrins of interest which could be identified by mass spectrometry as the methyl esters of porphyrins with ...

Patients with overt porphyria cutanea tarda (PCT) show a distinctive and abnormal urinary profile of porphyrin excretion. It is not known, however, whether clinical remission of the disease produces complete normalization of this profile. We selected 46 patients, previously diagnosed with PCT, who after treatment presented normal levels of total porphyrins in urine (< 35 nmol/mmol creatinine). ...

We recorded fluorescence excitation and emission spectra of uro- and coproporphyrin under different experimental conditions, to see how these conditions influence quantifications based on measurement of fluorescence intensity. We found that, for bands alpha and beta of the emission spectra and the main peak of the excitation spectra, fluorescence depends on pH and is minimal near pH 5 and near ...

In erythropoietic protoporphyria, accumulation of protoporphyrin has been found in various tissues and liver cirrhosis occurs frequently in this disease, probably due to toxic dark effects of protoporphyrin. We have studied the effect of porphyrins on various enzymic functions in rat liver microsomes. Incubation of microsomes with protoporphyrin resulted in a concentration-dependent inhibition ...

Adams, M., Richtmyer, N. K. & Hudson, C. S. (1943). J. Amer. chem. Soc. 65, 1369. Bacon, J. S. D. (1952). Biochem. J. 50, xviii. Bacon, J. S. D. & Edelman, J. (1951). Biochem. J. 48, 114. Bacon, J. S. D. & Loxley, R. (1952). Biochem. J. 51, 208. Bawden, F. C. & Pirie, N. W. (1942). Brit. J. exp. Path. 23, 314. Bealing, F. J. & Bacon, J. S. D. (1951). Biochem. J. 49, lxxv. Bealing, F. J. & Bacon...