AN IN-VITRO PHARMACOLOGICAL MODEL OF VASCULAR SMOOTH-MUSCLE

In order to develop an in vitro model of vascular tissue for pharmacol ogical studies, segments of porcine coronary arteries were incubated i n 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 wit h the fresh tissue. KCl (10-75 mM) and prostaglandin F2alpha (1-20 muM ) produced a similar concentration-dependent contraction in the incuba ted 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 fres h. Similarly, the relaxation responses to forskolin and sodium nitropr usside (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 bra dykinin (10(-7) M)-the endothelium-dependent agents-were also unaltere d in the incubated rings versus fresh. Therefore, we conclude that aft er the incubation of porcine coronary artery for 3 days, the contracti on/relaxation responses to various agonists acting through different m echanisms were unaltered in porcine coronary artery. This in vitro mod el of vascular smooth muscle provides a potential for pharmacological and toxicological studies.