Contractile characteristics of rat mesenteric artery after organ culture.

Organ culture of blood vessels is a useful technique to analyze long-term effects of drugs. Various growth factors are responsible for structural and functional changes during vascular remodeling. We investigated 1) basic contractile characteristics in organ-cultured rat mesenteric arteries (MA) in serum-free condition and 2) long-term effects of fetal bovine serum (FBS). Rat isolated MA with [E (+)] or without [E (-)] endothelium were divided into 1) freshly isolated (fresh), 2) cultured for 3 days without FBS (control) or 3) with 10% FBS (FBS). In E (+) control, maximal contraction by noradrenaline (NA), endothelin (ET)-1 and 5-hydroxytriptamine (5-HT) was similar to that in fresh. In E (-) control, maximal contraction by NA decreased whereas that by ET-1 and 5-HT didn't change from fresh. In E (+) FBS, maximal contraction by NA, ET-1, and 5-HT increased from control. In E (-) FBS, maximal contraction by NA and ET-1 decreased whereas that by 5-HT increased. In E (+) or E (-) control and FBS, sensitivity to NA and ET-1 increased from fresh. In E (+) and E (-) control, sensitivity to 5-HT decreased from fresh, and that in FBS further decreased from control. Three-day organ-cultured rat MA in serum-free condition preserved enough contraction to enable analysis for long-term effects of drug. In FBS, maximal contractions by NA and ET-1 increased in E (+) and decreased in E (-) from control, while those by 5-HT increased in both E (+) and E (-).