title: Vascular smooth muscle cell hyper-responsiveness to growth factors in hypertension.
abstract: To understand the intrinsic mechanisms of vascular smooth muscle cell proliferation, we studied the growth of cultured rat aortic smooth muscle from spontaneously hypertensive rats (SHR) and their normotensive controls, Wistar-Kyoto rats (WKY), under basal conditions and after stimulation. Cell growth was assessed by the determination of cell number, and incorporation of 3H-thymidine into newly-synthesized DNA. We demonstrated that vascular smooth muscle cells from SHR proliferate faster and grow to a greater density, regardless of the initial plating number. The growth difference was not due to different plating efficiencies. Significantly higher 3H-thymidine incorporation was observed in vascular smooth muscle cells from SHR when the cells were stimulated by calf serum, platelet-derived growth factor or epidermal growth factor. Exposure to calf serum elicited an excessive expression of c-myc and c-fos in the first hour after stimulation. These results provide evidence of the hyper-responsiveness of vascular smooth muscle cells from SHR aortae to growth stimuli.
authors.affiliation: Clinical Research Institute of Montreal, Quebec, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Hamet
authors.forename: V
authors.initials: V
authors.lastname: Hadrava
authors.forename: U
authors.initials: U
authors.lastname: Kruppa
authors.forename: J
authors.initials: J
authors.lastname: Tremblay
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis; D004815:Epidermal Growth Factor / Q000494:pharmacology; D006973:Hypertension / Q000473:pathology / Q000503:physiopathology*; D009131:Muscle, Smooth, Vascular / Q000473:pathology / Q000503:physiopathology*; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR
chemical_list: D010982:Platelet-Derived Growth Factor; D004815:Epidermal Growth Factor; D004247:DNA