Linked Life Data

10382866

Source:http://linkedlifedata.com/resource/pubmed/id/10382866

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1999-7-27
pubmed:abstractText
Aflatoxin B1 (AFB1) action on cyclic nucleotide phosphodiesterase (PDE) activity has been tested on tissue extracts of various organs. In the presence of 100 microM AFB1 a significant inhibition of cAMP and cGMP hydrolytic activity is observed in all tested tissue extracts. However, cGMP hydrolytic activity appears more sensitive to AFB1 inhibition than cAMP hydrolytic activity and a considerably higher inhibition is observed in lung and spleen, than in liver, brain, kidney, and heart. When cGMP is used as substrate, the inhibitory response reaches 72% in lung and spleen extracts. We have also tested AFB1 effects on lung and liver PDE activity peaks separated by DEAE-cellulose chromatography. These data confirm the poor sensitivity to the toxin of all PDE activities present in liver, while the lung peak (where PDE V in present) shows a higher sensitivity to AFB1. In order to establish whether PDE V is in fact more sensitive to AFB1, we have used mouse neuroblastoma cells, in which cGMP hydrolytic activity has been shown to be due to PDE V only. In this case, the calculated IC50 is 24 microM and Dixon plot analysis shows a competitive inhibitory effect with a Ki of 16.7 microM. We have also used aflatoxin B2 and M2, and they proved to be much less effective than AFB1: AFB2 inhibits PDE V with an IC50 of 117 microM, while AFM2 does not show any effect. These results provide the first evidence of a competitive inhibition of AFB1 on an enzymatic activity and suggest that an alteration of cellular cyclic nucleotide levels may play a role in the mechanism of aflatoxin action.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0306-3623
pubmed:author
pubmed:issnType
Print
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
615-9
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Aflatoxin B1 is an inhibitor of cyclic nucleotide phosphodiesterase activity.
pubmed:affiliation
Dipartimento de Biologia Cellulare e dello Sviluppo, Università di Roma La Sapienza, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't