Angiotensin-Converting Enzyme: Characteristics in Human Skin Fibroblasts.

摘要

Angiotensin-converting enzyme, although most prominent in vascular endothelium, has been identified in numerous tissues. Recent studies have indicated that several hormones, including glucocorticoids and thyroid hormone, may affect the activity of this enzyme. In the present study, angiotensin-converting enzyme was examined in homogenates of cultured human skin fibroblasts. Angiotensin-converting enzyme activity was measured by a radiometric assay using Glycine-1-14C protein. Angiotensin-converting enzyme was identified in all five cell stains tested. The optimum pH was between 6.9 and 7.6, and optimum temperature was 37 C, with loss of activity of 55 C and higher. The most potent inhibitor of fibroblast ACE was captopril other inhibitors included SQ 20,881, EDTA, and phenanthroline. Human skin fibroblasts have ACE activity similar in many respects to other tissues, although several hormones failed to affect the activity of this enzyme. Recent evidence in several tissues suggests there may be local, functioning renin-angiotensin systems. The presence of ACE in skin fibroblasts may indicate that such a system is available for local regulation of cutaneous vasoconstriction. Reprints.