Interleukin 6 stimulates growth of vascular smooth muscle cells in a PDGF-dependent manner

Am J Physiol. 1991 May;260(5 Pt 2):H1713-7. doi: 10.1152/ajpheart.1991.260.5.H1713.


We have investigated the effect of interleukin 6 (IL-6) on the growth of vascular smooth muscle cells (VSMC) isolated from rat aortas. Murine recombinant IL-6 significantly increased the number of VSMC and stimulated tritiated thymidine incorporation into VSMC in a dose-dependent manner. The IL-6-induced thymidine incorporation into VSMC was totally inhibited by the Ca2+ channel blocker verapamil; however, IL-6 showed no effects on the intracellular Ca2+ level ([Ca2+]i) in VSMC. Antibody against platelet-derived growth factor (PDGF) also totally inhibited the IL-6-induced thymidine uptake. PDGF caused a significant increase in the [Ca2+]i, which was totally inhibited by verapamil. IL-6 mRNA was not detected in unstimulated "quiescent" VSMC, but its expression was stimulated by exposure of VSMC to 10% fetal bovine serum. Immunohistochemical study using anti-PDGF antibody showed that IL-6 stimulated PDGF production in VSMC. These results support the premise that IL-6 is released by VSMC in an autocrine manner and promotes the growth of VSMC via induction of endogenous PDGF production.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies / immunology
  • Calcium / metabolism
  • Cell Division / drug effects
  • Immunohistochemistry / methods
  • Interleukin-6 / genetics
  • Interleukin-6 / pharmacology*
  • Muscle, Smooth, Vascular / cytology*
  • Muscle, Smooth, Vascular / metabolism
  • Osmolar Concentration
  • Platelet-Derived Growth Factor / immunology
  • Platelet-Derived Growth Factor / pharmacology*
  • RNA, Messenger / metabolism
  • Staining and Labeling


  • Antibodies
  • Interleukin-6
  • Platelet-Derived Growth Factor
  • RNA, Messenger
  • Calcium