Platelet-derived growth factor A-chain homodimer stimulated growth of cultured smooth muscle cells from spontaneously hypertensive rats.
Vascular smooth muscle cells from spontaneously hypertensive rats (SHR) were growth stimulated when cocultured with bovine aortic endothelial cells whereas myocytes from normotensive, Wistar Kyoto rats (WKY) were growth inhibited. The responsiveness of cells from the two rat sources to the two homodimeric forms of platelet-derived growth factor (PDGF-AA or -BB) was different; SHR-derived cells responding equally well to both PDGF forms whereas cells from WKY responded to the B-chain homodimer only. The responses measured included S6 kinase activation, phospholipase C mediated phosphoinositide catabolism and cell growth. Saturation binding experiments using [125I]-labelled PDGF homodimers (AA or BB) indicated that smooth muscle cells from hypertensive rats possess similar numbers of cell-surface A-chain receptors (alpha subunits) as Swiss 3T3 cells which have been used to characterize the mitogenic effects of the two PDGF homodimeric forms. The differences in responsiveness of SHR vs WKY cells to PDGF-AA and to the influence of endothelial cells may reside in their differential expression of PDGF receptors.
Scott-Burden
T
T
Center for Experimental Therapeutics, Baylor College of Medicine, Houston, Texas 77030.
Resink
T J
TJ
Hahn
A A
AA
Buhler
F R
FR
D000818:Animals; D001704:Biopolymers; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000502:physiology; D006973:Hypertension / Q000235:genetics / Q000503:physiopathology*; D024510:Muscle Development; D009130:Muscle, Smooth / Q000254:growth & development*; D010446:Peptide Fragments / Q000502:physiology*; D010766:Phosphorylation; D010982:Platelet-Derived Growth Factor / Q000502:physiology*; D011494:Protein Kinases / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D019893:Ribosomal Protein S6 Kinases
D001704:Biopolymers; D010446:Peptide Fragments; D010982:Platelet-Derived Growth Factor; D011494:Protein Kinases; D019893:Ribosomal Protein S6 Kinases