Insulin-like growth factor binding proteins in arterial XXXX : relationship to @entity4346 .

@entity1 @entity4346 @entity101
OBJECTIVE: It was reported previously that circulating insulin-like growth factor I levels are abnormally elevated in @entity1 with essential @entity101 and @entity4346 . Tissue availability of the factor depends on the distribution of the circulating bound factor between its high- and low-molecular mass binding proteins, only the latter being able to cross the endothelium. The aim of this study was to investigate whether the presence of the different serum binding proteins is altered in @entity1 with essential @entity101 and @entity4346 . DESIGN: The study was performed in 30 never-treated @entity1 with essential @entity101 and 30 age- and sex-matched normotensive subjects. @entity1 were separated into two groups according to the presence or the absence of echocardiographically determined @entity4346 . METHODS: Plasma insulin-like growth factor I levels were determined by specific radioimmunoassay. The different molecular forms of its serum binding proteins were analysed by Western blotting using [125I]-labelled insulin-like growth factor I. A densitometric scanning of the blots was performed to analyse the quantitative relationships between the different forms of binding proteins. RESULTS: Insulin-like growth factor I levels were significantly higher in the @entity101 @entity1 with than in the @entity101 @entity1 without @entity4346 or in the normotensive subjects. Compared with the normotensive subjects, both @entity101 @entity1 subgroups exhibited increased high-molecular mass binding protein type 3 and decreased low-molecular mass binding proteins types 1 and 2. However, changes in the binding proteins were more marked in the @entity101 @entity1 without than in the @entity101 @entity1 with @entity4346 . Accordingly, the ratio of low- to high-molecular mass binding proteins (an index of insulin-like growth factor I bioavailability) was higher in the @entity101 @entity1 with than in the @entity101 @entity1 without @entity4346 . CONCLUSIONS: These results show that the distribution of the molecular forms of serum insulin-like growth factor binding proteins is altered in @entity1 with essential @entity101 , independently of insulin-like growth factor I levels. This suggests that regulation of the binding proteins is abnormal in essential @entity101 . Whether the tissue availability of circulating insulin-like growth factor I is higher in @entity101 @entity1 with than in @entity101 @entity1 without @entity4346 merits further investigation.
