Polypeptide levels increase during acute onset of hepatic porphyrias
Medenica, R.; Lazovic, G.; Huschart, T.; Mukerjee, S.; Long, P.; Corbitt, W.; Powell, D.
Cellular and Molecular Biology 43(1): 9-27
1997
ISSN/ISBN: 0145-5680 PMID: 9074785 Document Number: 475943
Hepatic porphyrias are characterized by neurological symptoms manifested by abdominal pain, neuropathies and mental aberrations. Porphyrins are ubiquitous and essential biochemical constituents of living beings acting as mediators of oxidation reaction in the metabolism of the steroid, drugs, environmental chemicals or as a mean of exchanging gases, such as oxygen and carbon dioxide between the environment and the tissue of the body using endogenous polypeptide properties. The different porphyrins arising from the arrangement of normal heme synthesis are characterized by an accumulation and excretion of specific intermediate porphyrins and/or of precursors exerting toxic effect, initiating cascades of generations of polypeptides, neurotransmitters and gut-brain axis peptide responsible for the symptoms of clinical status. We studied polypeptide levels in 27 patients (19 females, 8 males) presenting acute attack of hepatic porphyria: 2 with ALA dehydratase-deficient porphyria; 9 with acute intermittent porphyria; 12 with porphyria cutanea tarda and 4 with variegate porphyria. During acute attacks of porphyria, polypeptides were found to be constantly increased: vasoactive intestinal polypeptide (VIP); neurotensin (NT); substance P; pancreatic polypeptide; gastrin-releasing peptide; gastrin and motilin. Administration of the somatostatin (antagonizing polypeptide), which was undetectable or low before treatment, apparently alleviated the acute symptomatology. Elevated levels of polypeptides, at least partly, contribute to appearance of acute symptoms in porphyria patients.