Regulation of renin-like enzyme in cultured human vascular smooth muscle cells

Cultured human arterial smooth muscle cells produced an immunologically specific renin-like enzyme. The renin-like enzyme in the culture medium was mostly an inactive form; the proportion of the active form in the cell was 30 to 75%. Phorbol 12-myristate 13-acetate, N'-O'-dibutylyladenosine 3', 5'-monophosphate and isoproterenol with theophylline increased the renin-like enzyme in the medium and in the cell, dose dependently. Endothelial cell growth supplement also increased the renin-like enzyme produced by cultured vascular smooth muscle cells, and heparin promoted the effects of endothelial cell growth supplement. The existence of the regulation of the renin-like enzyme produced by cultured vascular smooth muscle cells strongly suggests the existence of a local renin angiotensin system in human vascular walls.