Elastin synthesis is inhibited by angiotensin II but not by platelet-derived growth factor in arterial smooth muscle cells.
Effects of two major potent vasoconstrictors, angiotensin II and platelet-derived growth factor, on elastin expression in cultured chick embryonic arterial smooth muscle cells were studied. Platelet-derived growth factor exhibited no effect on elastin synthesis nor its mRNA level but stimulated (1.5-fold) cell proliferation slightly. Angiotensin II inhibited elastin synthesis dose- and time-dependent manner with a maximum suppression of sixty percent of control at a concentration of 10 microM for 18 h treatment. The suppression was accompanied with a comparable decrease in elastin mRNA level. The inhibition was blocked by addition of Sar1,Ala8-angiotensin II and 8-bromo-cGMP. It showed no effect on cell proliferation. Angiotensin II appears to inhibit elastin synthesis through the interaction with its receptor and the modulation of intracellular Ca2+ level. Thus angiotensin II, not platelet-derived growth factor, can exert a profound effect on the extracellular matrix composition in arterial walls, leading to an arterial change in hypertension or atherosclerosis.
Tokimitsu
I
I
Department of Dermatology, Keio University School of Medicine, Tokyo, Japan.
Kato
H
H
Wachi
H
H
Tajima
S
S
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D002455:Cell Division; D002478:Cells, Cultured; D002642:Chick Embryo; D003094:Collagen / Q000096:biosynthesis; D004549:Elastin / Q000096:biosynthesis*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*
D010982:Platelet-Derived Growth Factor; D000804:Angiotensin II; D003094:Collagen; D004549:Elastin