The typical biochemical findings include elevated levels of
uroporphyrin in urine with levels even upto sixty times the normal.
The activation of
uroporphyrin deposited in the skin by ultraviolet light induces the production of oxidized reactive substances that excessively activate collagenase.
It also implies increased plasma or urine porphyrins formed before the UROD step such as
uroporphyrin, heptacarboxylporphyrin, hexacarboxylporphyrin, and pentacarboxylporphyrin (urine analysis not validated for patients with end-stage renal disease (ESRD)) with concomitant normal levels of coproporphyrins [7].
It results in an increase in
uroporphyrin I and coproporphyrin I in plasma, red blood cells, urine, feces, and in different tissues.
Differential potency of atropisomers of polychlorinated biphenyls on cytochrome P450 induction and
uroporphyrin accumulation in the chick embryo hepatocyte culture.
The combination of elevated urinary and erythrocyte
uroporphyrin I levels is specific for EP.
The steps in the heme synthesis pathway that are most vulnerable to heavy metal inhibition are those that involve the enzymes
uroporphyrin decarboxylase (UROD) and coproporphyrinogen oxidase (CPOX).
Results similar to those for HPD were obtained by others [20] (in the same buffer, but at 25[degrees]C) with PII (5.4 x [10.sup.-5]) and typical porphyrins (HP, 4.7 x [10.sup.-5];
uroporphyrin, 2.8 x [10.sup.-5]).
ALA is the pre-porphyrin aminolevulinic acid; UP is
uroporphyrin; and CP is coproporphyrin.
Urine porphyrins were shown on thin-layer chromatography (TLC) to be mostly
uroporphyrin with a trace of heptacarboxylic porphyrin.
Congenital erythropoietic porphyria (CEP) is one of the rare forms of an intriguing group of metabolic disorders known as porphyria, caused by an autosomal recessive inherited deficiency of the
uroporphyrin III cosynthase enzyme.
CYP3A-inducing agents and the attenuation of
uroporphyrin accumulation and excretion in a rat model of porphyria cutanea tarda.
