INTERACTION BETWEEN PLASMA-LIPOPROTEINS AND VASCULAR SMOOTH-MUSCLE CELLS - HOW RELEVANT IS IT TO ARTERIAL-HYPERTENSION

Hypertension induces arterial changes markedly similar to those observ ed in atherosclerosis, including endothelial changes, leukocyte adhere nce and penetration, macrophage accumulation, increased permeability t o plasma lipids, smooth muscle cell migration, and intimal smooth musc le cell proliferation and accumulation. The close relationship between hypertension and atherosclerosis may reflect a common, intricate netw ork of molecules (pressor-growth hormones and peptides) and cellular s ignalling mechanisms that potentially regulate vascular events. This p aper focusses on the possibility that lipoproteins, whose role in athe rogenesis is well established, may also be physiologically modulators of blood pressure regulation. In particular we review the evidence in support of direct stimulatory effects of lipoproteins on contraction-c oupled and replication-coupled signalling mechanisms in vascular smoot h muscle cells. Since such pressor-trophic properties of lipoproteins are expected to influence both functional and structural aspects of th e vasculature, it is hypothesized that interactions between lipoprotei ns and vascular smooth muscle cells may be relevant to hypertension.