Biomaterial Database

Porphyrin metabolism and haem biosynthesis in Gilbert's syndrome. 1987

K E McColl, and G G Thompson, and E el Omar, and M R Moore, and A Goldberg

Studies in 14 patients with unconjugated hyperbilirubinaemia caused by Gilbert's syndrome have revealed abnormalities of the enzymes of haem biosynthesis measured in peripheral blood cells. The activity of the penultimate enzyme of haem biosynthesis protoporphyrinogen (PROTO) oxidase was reduced at 3.1 +/- 2.6 nmol PROTO/g protein/h (mean +/- ISD) compared with 8.2 +/- 5.1 in controls (p less than 0.005). This was associated with a compensatory increase in the activity of the initial and rate controlling enzyme of the pathway delta-aminolaevulinic acid (ALA) synthase at 866 +/- 636 nmol ALA/g/protein/h compared with 156 +/- 63 in controls (p less than 0.001). Unlike variegate porphyria in which there is a genetic deficiency of PROTO oxidase there was no increased excretion of porphyrins or their precursors in Gilbert's syndrome. Accentuation and subsequent correction of the unconjugated hyperbilirubinaemia with rifampicin produced reciprocal changes in PROTO oxidase activity indicating that bilirubin may be inhibiting the activity of this enzyme.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D010088	Oxidoreductases	The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)	Dehydrogenases,Oxidases,Oxidoreductase,Reductases,Dehydrogenase,Oxidase,Reductase
D011164	Porphyrias	A diverse group of metabolic diseases characterized by errors in the biosynthetic pathway of HEME in the LIVER, the BONE MARROW, or both. They are classified by the deficiency of specific enzymes, the tissue site of enzyme defect, or the clinical features that include neurological (acute) or cutaneous (skin lesions). Porphyrias can be hereditary or acquired as a result of toxicity to the hepatic or erythropoietic marrow tissues.	Porphyria,Porphyrin Disorder,Disorder, Porphyrin,Disorders, Porphyrin,Porphyrin Disorders
D011166	Porphyrins	A group of compounds containing the porphin structure, four pyrrole rings connected by methine bridges in a cyclic configuration to which a variety of side chains are attached. The nature of the side chain is indicated by a prefix, as uroporphyrin, hematoporphyrin, etc. The porphyrins, in combination with iron, form the heme component in biologically significant compounds such as hemoglobin and myoglobin.	Porphyrin
D005260	Female		Females
D005420	Flavoproteins		Flavoprotein
D005878	Gilbert Disease	A benign familial disorder, transmitted as an autosomal dominant trait. It is characterized by low-grade chronic hyperbilirubinemia with considerable daily fluctuations of the bilirubin level.	Constitutional Liver Dysfunction,Familial Nonhemolytic Jaundice,Gilbert Syndrome,Gilbert's Disease,Gilbert's Syndrome,Gilbert-Lereboullet Syndrome,Hyperbilirubinemia 1,Hyperbilirubinemia I,Hyperbilirubinemia, Arias Type,Meulengracht Syndrome,Unconjugated Benign Bilirubinemia,Arias Type Hyperbilirubinemia,Arias Type Hyperbilirubinemias,Disease, Gilbert,Disease, Gilbert's,Gilberts Disease,Gilberts Syndrome,Hyperbilirubinemia 1s,Hyperbilirubinemias, Arias Type,Syndrome, Gilbert,Syndrome, Gilbert's
D006418	Heme	The color-furnishing portion of hemoglobin. It is found free in tissues and as the prosthetic group in many hemeproteins.	Ferroprotoporphyrin,Protoheme,Haem,Heme b,Protoheme IX
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man