Effects of long-term administration of (4S)-1-methyl-3-[(2S)-2-[N-((1S)-1-ethoxycarbonyl-3- phenylpropyl)amino]propionyl]-2-oxoimidazolidine-4-carboxylic acid hydrochloride (TA-6366), a new angiotensin I converting enzyme (ACE) inhibitor, from the pre-hypertensive stage on morphological change and mechanical property related to sodium ion permeability in aorta of spontaneously hypertensive rats (SHRs).