Linked Life Data

1659819

Source:http://linkedlifedata.com/resource/pubmed/id/1659819

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1991-12-31
pubmed:abstractText
The antitumor agents cisplatin [cis-diamminedichloroplatinum(II), CDDP] and carboplatin [cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II), CBDCA] can react with a nucleophilic agent by a direct ligand exchange of the (labile) anionic ligands or through hydrolysis of these ligands followed by a fast reaction of the hydration product with the nucleophile. At pH 7.4 and 37 degrees, CDDP and CBDCA were incubated with several molar excesses of the modulating agent WR2721, its active thiol metabolite WR1065 or the symmetrical disulphide WR33278. The reaction rate constants for the hydrolysis and the direct inactivation by the WR-compounds were obtained from the pseudo first-order disappearance of the intact Pt-drug, with or without the WR-compounds at molar ratios of 50, 100 and 200. The hydrolysis of carboplatin (kaq,CBDCA = 2 x 10(-8) M-1 sec-1) was 100-fold less rapid than that of cisplatin (kaq,CDDP = 2 x 10(-6) M-1 sec-1). However, direct inactivation by WR2721, WR1065 and WR33278 was only 4-, 4- and 22-fold less rapid for carboplatin than for cisplatin, respectively. This direct inactivation was slow compared to the strong nucleophiles thiosulphate (TS) and diethyldithiocarbamate (DDTC) and decreased for both Pt-drugs in the following order: WR1065 (kWR1065/CDDP = 49.1 x 10(-4) M-1 sec-1, kWR1065/CBDCA = 12.4 x 10(-4) M-1 sec-1) greater than WR2721 (kWR2721/CDDP = 25.3 x 10(-4) M-1 sec-1, kWR2721/CBDCA = 6.07 x 10(-4) M-1 sec-1) greater than WR33278 (kWR33278/CDDP = 8.60 x 10(-4) M-1 sec-1, kWR33278/CBDCA = 0.39 x 10(-4) M-1 sec-1. Thus for CDDP, the hydrolysis-mediated interaction with the WR-compounds contributed more to the disappearance of intact platinum antitumor agent than it did for CBDCA. Considering the relatively low reactivity of WR2721 and its main metabolites with the platinum antitumor agents, in addition to their pharmacokinetic behavior, a significant inactivation of the platinum antitumor drugs by WR2721 and its main metabolites is, in contrast to TS, not expected in the circulation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-2952
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2125-30
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
The chemical reactivity of the modulating agent WR2721 (ethiofos) and its main metabolites with the antitumor agents cisplatin and carboplatin.
pubmed:affiliation
Department of Oncology, Free University Hospital, Amsterdam, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't