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Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1982 Jun;79(12):3863–3866. doi: 10.1073/pnas.79.12.3863

Vascular smooth muscle cell growth kinetics in vivo in aged rats.

M B Stemerman, R Weinstein, J W Rowe, T Maciag, R Fuhro, R Gardner
PMCID: PMC346528  PMID: 6954528

Abstract

Age is a risk factor in the development of atherosclerosis. In this study we investigated the hypothesis that proliferation of vascular smooth muscle cells (SMCs), an integral part of atherosclerotic plaque formation, changes with age. SMC growth kinetics of old rats (21-24 months) were compared to those of young adult rats (3-4 months). Rat aortas were denuded of their endothelium and the animals were killed after [3H]thymidine and Evans blue injections at 0-28 days after denudation. Incorporation of [3H]thymidine into SMC peaked in the young animals by day 2, whereas the older animals responded to endothelial removal with greater incorporation at day 2 and a more sustained rate of incorporation peaking at day 4. The [3H]thymidine incorporation curves decreased sharply from their peaks at 2 and 4 days, respectively, and paralleled each other after day 7. [3H]Thymidine uptake reflected the subsequent SMC intimal growth as measured morphometrically, with old animals showing greater numbers of intimal SMC than did the younger animals. The difference in response of SMC to injury with age suggests that aging produces a change in the vascular SMC that enhances proliferation. This change in response implies that the more pronounced atherosclerotic plaque growth seen with aging may be a result of an age-related increase in response to injury rather than merely the accumulation of time-related intimal change.

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Selected References

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  1. Benditt E. P., Benditt J. M. Evidence for a monoclonal origin of human atherosclerotic plaques. Proc Natl Acad Sci U S A. 1973 Jun;70(6):1753–1756. doi: 10.1073/pnas.70.6.1753. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bettmann M. A., Stemerman M. B., Ransil B. J. The effect of hypophysectomy on experimental endothelial cell regrowth and intimal thickening in the rat. Circ Res. 1981 Jun;48(6 Pt 1):907–912. doi: 10.1161/01.res.48.6.907. [DOI] [PubMed] [Google Scholar]
  3. Goldberg I. D., Stemerman M. B., Ransil B. J., Fuhro R. L. In vivo aortic muscle cell growth kinetics. Differences between thoracic and abdominal segments after intimal injury in the rabbit. Circ Res. 1980 Aug;47(2):182–189. doi: 10.1161/01.res.47.2.182. [DOI] [PubMed] [Google Scholar]
  4. Goldberg I. D., Stemerman M. B., Schnipper L. E., Ransil B. J., Crooks G. W., Fuhro R. L. Vascular smooth muscle cell kinetics: a new assay for studying patterns of cellular proliferation in vivo. Science. 1979 Aug 31;205(4409):920–922. doi: 10.1126/science.472713. [DOI] [PubMed] [Google Scholar]
  5. HAYFLICK L. THE LIMITED IN VITRO LIFETIME OF HUMAN DIPLOID CELL STRAINS. Exp Cell Res. 1965 Mar;37:614–636. doi: 10.1016/0014-4827(65)90211-9. [DOI] [PubMed] [Google Scholar]
  6. Issler R. W. The arterial medial cell, smooth muscle or multifunctional mesenchyme? J Atheroscler Res. 1968 Mar-Apr;8(2):201–213. doi: 10.1016/s0368-1319(68)80056-0. [DOI] [PubMed] [Google Scholar]
  7. Lesser G. T., Deutsch S., Markofsky J. Aging in the rat: longitudinal and cross-sectional studies of body composition. Am J Physiol. 1973 Dec;225(6):1472–1478. doi: 10.1152/ajplegacy.1973.225.6.1472. [DOI] [PubMed] [Google Scholar]
  8. Martin G. M., Sprague C. A. Symposium on in vitro studies related to atherogenesis. Life histories of hyperplastoid cell lines from aorta and skin. Exp Mol Pathol. 1973 Apr;18(2):125–141. doi: 10.1016/0014-4800(73)90012-9. [DOI] [PubMed] [Google Scholar]
  9. Ross R., Glomset J. A. The pathogenesis of atherosclerosis (first of two parts). N Engl J Med. 1976 Aug 12;295(7):369–377. doi: 10.1056/NEJM197608122950707. [DOI] [PubMed] [Google Scholar]
  10. Stemerman M. B., Ross R. Experimental arteriosclerosis. I. Fibrous plaque formation in primates, an electron microscope study. J Exp Med. 1972 Oct 1;136(4):769–789. doi: 10.1084/jem.136.4.769. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Stemerman M. B., Spaet T. H., Pitlick F., Cintron J., Lejnieks I., Tiell M. L. Intimal healing. The pattern of reendothelialization and intimal thickening. Am J Pathol. 1977 Apr;87(1):125–142. [PMC free article] [PubMed] [Google Scholar]
  12. Stemerman M. B. Thrombogenesis of the rabbit arterial plaque. An electron microscopic study. Am J Pathol. 1973 Oct;73(1):7–26. [PMC free article] [PubMed] [Google Scholar]
  13. Tiell M. L., Stemerman M. B., Spaet T. H. The influence of the pituitary on arterial intimal proliferation in the rat. Circ Res. 1978 May;42(5):644–649. doi: 10.1161/01.res.42.5.644. [DOI] [PubMed] [Google Scholar]

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