Vascular structure, smooth muscle cell phenotype and growth in hypertension.

The media of most blood vessels is occupied by vascular smooth muscle cells. In areas they may be replaced by glomus cells, pericytes or renin-secreting myoepithelioid cells. These cells may be regarded as phenotypic variants of vascular smooth muscle cells. In disease, ordinary vascular smooth muscle cells may also assume a spectrum of phenotypes ranging from contractile to largely secretory types. Therefore, the phenotype of smooth muscle cells that is involved in a disease process such as hypertension or one of its complications is likely to affect the structural outcome in blood vessels.