Study of the relationship between endogenous protoporphyrin IX concentration in human lymphoblastoid cells and inactivation by UVA radiation

R D Watkin, Rex M Tyrrell

Research output: Contribution to journalArticle

Abstract

Intracellular content of the endogenous chromophore protoporphyrin IX (PPIX) can be modulated by administration of the haem precursor delta-aminolevulinic acid (ALA). Exogenous addition of ALA effectively bypasses the rate limiting ALA synthesis step in the haem biosynthetic pathway leading to the accumulation of PPIX. The purpose of this study was to examine the relationship between PPM concentration and the level of inactivation of cultured human lymphoblastoid cells in order to determine if the basal PPIX content of these cells determines the level of inactivation by WA. From the relationship between inactivation rate constants at each PPIX concentration an estimate was made of the basal level of PPIX that would be necessary to mediate significant cell death by UVA radiation. It is concluded that the basal content of PPM is insufficient to make a major contribution to the WA inactivation of these lymphoblastoid cells.
Original languageEnglish
Pages (from-to)85-88
Number of pages4
JournalRadiation Protection Dosimetry
Volume91
Issue number1-3
Publication statusPublished - 2000

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deactivation
Aminolevulinic Acid
Radiation
pulse position modulation
radiation
cells
acids
Heme
bypasses
death
chromophores
Biosynthetic Pathways
Cell Death
protoporphyrin IX
synthesis
estimates

Cite this

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title = "Study of the relationship between endogenous protoporphyrin IX concentration in human lymphoblastoid cells and inactivation by UVA radiation",
abstract = "Intracellular content of the endogenous chromophore protoporphyrin IX (PPIX) can be modulated by administration of the haem precursor delta-aminolevulinic acid (ALA). Exogenous addition of ALA effectively bypasses the rate limiting ALA synthesis step in the haem biosynthetic pathway leading to the accumulation of PPIX. The purpose of this study was to examine the relationship between PPM concentration and the level of inactivation of cultured human lymphoblastoid cells in order to determine if the basal PPIX content of these cells determines the level of inactivation by WA. From the relationship between inactivation rate constants at each PPIX concentration an estimate was made of the basal level of PPIX that would be necessary to mediate significant cell death by UVA radiation. It is concluded that the basal content of PPM is insufficient to make a major contribution to the WA inactivation of these lymphoblastoid cells.",
author = "Watkin, {R D} and Tyrrell, {Rex M}",
note = "International Workshop on Ultraviolet Radiation Exposure, Measurement and Protection. 18-20 October 1999. Oxford, England",
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language = "English",
volume = "91",
pages = "85--88",
journal = "Radiation Protection Dosimetry",
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publisher = "Oxford University Press",
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TY - JOUR

T1 - Study of the relationship between endogenous protoporphyrin IX concentration in human lymphoblastoid cells and inactivation by UVA radiation

AU - Watkin, R D

AU - Tyrrell, Rex M

N1 - International Workshop on Ultraviolet Radiation Exposure, Measurement and Protection. 18-20 October 1999. Oxford, England

PY - 2000

Y1 - 2000

N2 - Intracellular content of the endogenous chromophore protoporphyrin IX (PPIX) can be modulated by administration of the haem precursor delta-aminolevulinic acid (ALA). Exogenous addition of ALA effectively bypasses the rate limiting ALA synthesis step in the haem biosynthetic pathway leading to the accumulation of PPIX. The purpose of this study was to examine the relationship between PPM concentration and the level of inactivation of cultured human lymphoblastoid cells in order to determine if the basal PPIX content of these cells determines the level of inactivation by WA. From the relationship between inactivation rate constants at each PPIX concentration an estimate was made of the basal level of PPIX that would be necessary to mediate significant cell death by UVA radiation. It is concluded that the basal content of PPM is insufficient to make a major contribution to the WA inactivation of these lymphoblastoid cells.

AB - Intracellular content of the endogenous chromophore protoporphyrin IX (PPIX) can be modulated by administration of the haem precursor delta-aminolevulinic acid (ALA). Exogenous addition of ALA effectively bypasses the rate limiting ALA synthesis step in the haem biosynthetic pathway leading to the accumulation of PPIX. The purpose of this study was to examine the relationship between PPM concentration and the level of inactivation of cultured human lymphoblastoid cells in order to determine if the basal PPIX content of these cells determines the level of inactivation by WA. From the relationship between inactivation rate constants at each PPIX concentration an estimate was made of the basal level of PPIX that would be necessary to mediate significant cell death by UVA radiation. It is concluded that the basal content of PPM is insufficient to make a major contribution to the WA inactivation of these lymphoblastoid cells.

M3 - Article

VL - 91

SP - 85

EP - 88

JO - Radiation Protection Dosimetry

JF - Radiation Protection Dosimetry

SN - 0144-8420

IS - 1-3

ER -