An in vitro pharmacological model of vascular smooth muscle

In order to develop an in vitro model of vascular tissue for pharmacological studies, segments of porcine coronary arteries were incubated in culture media under sterile conditions in cell culture incubator at 37 degrees C with 95% O2 + 5% CO2. After 3 days of incubation, changes in isometric tension were measured in vascular rings and compared with the fresh tissue. KCl (10-75 mM) and prostaglandin F2 alpha (1-20 microM) produced a similar concentration-dependent contraction in the incubated and fresh arteries. The concentration-dependent relaxation curves produced by 2-chloroadenosine (10(-8) to 10(-4) M) and isoproterenol (10(-8) to 10(-5) M) were unaltered in the incubated tissue versus fresh. Similarly, the relaxation responses to forskolin and sodium nitroprusside (10(-8) to 10(-5) M) were unaffected in the incubated arteries. The relaxations produced by substance P (10(-12) to 10(-8) M) and bradykinin (10(-7) M)--the endothelium-dependent agents--were also unaltered in the incubated rings versus fresh. Therefore, we conclude that after the incubation of porcine coronary artery for 3 days, the contraction/relaxation responses to various agonists acting through different mechanisms were unaltered in porcine coronary artery. This in vitro model of vascular smooth muscle provides a potential for pharmacological and toxicological studies.