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Binding and growth‐inhibitory effect of heparin and oligo‐heparin (2 kDa) in Balb/c 3T3 cells: lack of effect on PDGF‐ or serum‐induced inositol lipid turnover
Author(s) -
Cavari Simone,
Fiorelli Gianna,
Vannucchi Simonetta
Publication year - 1994
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1994.tb16202.x
Subject(s) - heparin , chemistry , biochemistry , microbiology and biotechnology , biology
1 The ability of heparins (bovine heparin sm 1026, Av. mol. wt. 36.9 kDa and bovine heparin EP 756, Av. mol. wt. 12.9 kDa) and heparin fractions of different molecular weights (low molecular weight heparin, LMW 2123/OP, Av. mol. wt. 4.5 kDa and oligo‐heparin, Av. mol. wt. 2 kDa) to inhibit the proliferation and signalling of Balb/c 3T3 fibroblasts was investigated. 2 Heparin and heparin fractions of 4.5 and 2 kDa significantly inhibited DNA synthesis as monitored by [ 3 H]‐thymidine incorporation. 3 3 H‐labelled heparin fractions of 4.5 and 2 kDa were prepared by gel‐chromatography fractionation on Sephadex G‐75 of an 3 H‐labelled commercial heparin after treatment with heparinase. 4 The binding of unfractionated and oligo‐heparin of 2 kDa to Balb/c 3T3 fibroblasts was studied; we determined the specificity of heparin and oligo‐heparin binding to the cells by means of displacement of bound 3 H‐labelled compound in response to increasing concentrations of unlabelled compounds. Scatchard analysis of binding data obtained using [ 3 H]‐heparin as ligand revealed the presence of a single class of high affinity binding sites ( K d = 28 n m ) for heparin. Scatchard analysis of binding data obtained using [ 3 H]‐oligo‐heparin as ligand revealed the presence of a single class of low affinity binding sites ( K d = 3.2 μ m ) for oligo‐heparin. 5 In addition heparin displaced [ 3 H]‐oligo‐heparin at a concentration of approximately 100 fold of the K d determined in displacement studies. Furthermore, oligo‐heparin significantly displaced [ 3 H]‐heparin at a concentration of approximately 10 fold of the K d determined by displacement studies. 6 Both heparin and oligo‐heparin exert their inhibitory effects on Balb/c 3T3 DNA synthesis stimulated by PDGF or serum. However these molecules did not affect the inositol lipid turnover triggered by PDGF at a concentration which did not produce maximal response. The increase of inositol phosphate metabolism produced by 20% serum was also unaffected by heparin. This concentration of serum elicited a response comparable to that induced by a submaximal concentration of PDGF.