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Carnitine prevents cyclic GMP‐induced inhibition of peroxisomal enzyme activities
Author(s) -
Dhaunsi Gursev S.,
AlEssa Mazen,
Ozand Pinar T.,
Moosa Allie
Publication year - 2004
Publication title -
cell biochemistry and function
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 61
eISSN - 1099-0844
pISSN - 0263-6484
DOI - 10.1002/cbf.1117
Subject(s) - peroxisome , biochemistry , catalase , enzyme , microbody , peroxisomal disorder , acyltransferase , dihydroxyacetone phosphate , biology , zellweger syndrome , carnitine , chemistry , receptor
Peroxisomes, also termed as microbodies, are now known to carry out several specialized metabolic activities that are vital to cellular function. A defect in peroxisomal function leads to development of a fatal human disease, and a number of peroxisomal disorders are now linked to inherited peroxisomal enzyme abnormalities. Peroxisomal enzyme activities are also altered during pathophysiological conditions through various endogenously produced bio‐molecules such as nitric oxide (NO). NO produced by cytokines or NO‐donors is known to modulate peroxisomal functions, and these effects of NO are mediated through cGMP. We are reporting for the first time that L ‐carnitine (1–5 mm) prevents cGMP‐mediated impairment of peroxisomal enzyme activities. Cyclic GMP (250–1000 μ M ) significantly inhibited ( p < 0.01) the specific activities of catalase, acyl CoA oxidase and dihydroxyacetone‐phosphate acyltransferase (DHAPATase) in human dermal fibroblasts, and treatment of cells with 1–5 m M of carnitine significantly ( p < 0.001) reduced the inhibitory effects of cGMP on peroxisomal enzyme activities. These findings suggest that carnitine, previously thought to participate only in fatty acid oxidation, may in fact be regulating other cellular events including oxidative stress, and could possibly be used to correct cytokine‐impaired peroxisomal functions. Copyright © 2004 John Wiley & Sons, Ltd.