Enhanced growth rate of cultured smooth muscle cells from spontaneously hypertensive rats
Smooth muscle cells were isolated and cultured from the aortic media of age-matched, stroke-prone and stroke-resistant spontaneously hypertensive rats (SHRSP, SHRSR: SHRs) and Wistar-Kyoto rats (WKY), and the growth rate of cells from the three strains was compared. Under electron microscopical observation the cells were identified as modified (or synthetic-type) smooth muscle cells. Cells occurring at low densities showed the same morphology for both SHRs and WKY, but cells occurring at higher densities were observed to be smaller in SHRs than in WKY. An analysis of the growth curves of cells showed a significantly enhanced replication rate in cells from SHRs compared with those from WKY, especially in the early passages. In later passages (repeated until the 9th passage), however, this distinction was not clear. These growth characteristics were also confirmed in cells from both 12- and 24-week-old, age-matched SHRs and WKY. We could not find any difference between the growth characteristics of cells from SHRSP and SHRSR. It is possible to hypothesize from these findings that the abnormality relating to hypertension (hypertension being a common characteristic of SHRSR and SHRSP) is found in the smooth muscle cells, and is reflected as an enhanced growth rate when they are exposed to mitogenic stimuli, such as in atherosclerosis.
Key wordsHypertension Spontaneously hypertensive rats Cultured smooth muscle cells Growth rate
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- 1.Sternby NH (1977) Atherosclerosis and risk factors. In: Schettler et al. (eds) Atherosclerosis IV. Springer, Berlin Heidelberg New York, pp 102–104Google Scholar
- 2.Hypertension Detection and Follow-up Program Cooperative Group (1979) Five-year findings of the hypertension detection and follow-up program. I. Reduction in mortality of persons with high blood pressure, including mild hypertension. JAMA 242: 2562Google Scholar
- 4.Yamori Y (1983) Physiopathology of the various strains of spontaneously hypertensive rats. In: Gegest J et al. (eds) Hypertension—physiopathology and treatment, 2nd edn. McGraw-Hill, New York, p 556Google Scholar
- 8.Simpson FO, Waal-Manning HJ, Bolli P (1978) Relationship of blood pressure to sodium excretion in a population survey. Clin Sci Mol Med 55: 373Google Scholar
- 9.Igawa T, Nara Y, Kihara M, Horie R, Yamori Y (1983) Cellular mechanisms of salt sensitivity in hypertension. NZ Med J 96: 859–860Google Scholar