Due to anti-fibrotic activity of minoxidil inhibition of enzyme lysyl hydroxylase present in fibroblast may result in synthesis of a hydroxylysine-deficient collagen. Minoxidil can also potentially stimulate elastogenesis in aortic smooth muscle cells, and in skin fibroblasts in a dose-dependent manner. In hypertensive rats, minoxidil increases elastin level in the mesenteric, abdominal, and renal arteries by a decrease in "elastase" enzyme activity in these tissues. In rats, potassium channel openers decrease calcium influx which inhibits elastin gene transcription through extracellular signal-regulated kinase ½ (ERK 1/2)-activator protein 1 signaling pathway. ERK 1/2 increases, through elastin gene transcription, adequately cross-linked elastic fiber content synthetized by smooth muscle cells, and decreases the number of cells in the aorta.