Background/Aim: There have been different experimental conditions for in vitro
studies on human umbilical arteries (HUA) in tissue bath system. This diversity
was mainly reflected in variables such as stretching tension, incubation period and
initial constriction challenging with potassium (KCl). The aim of the study was to
establish optimal experimental conditions which will provide better responsiveness of HUA preparations, as well as to examine the impact of 24 h cold storage on
viability and responsiveness of HUA to KCl and serotonin.
Methods: The KCl-induced constrictions at different stretching tensions (0.5 g, 1.0
g, 2.0 g, 4.0 g), incubation times (30 min, 60 min, 120 min), and after multiple initial
constriction challenging were compared. Dose response curves for serotonin were
obtained under different conditions (1.0 g and 60 min vs. 2.0 g and 120 min). The
influence of 24 h cold storage on KCl- and serotonin- induced vasoconstriction of
HUA preparations was examined as well.
Results: The strongest constrictions induced by serotonin or KCl were obtained
when preparations were adjusted at 2.0 g and incubated for 120 min. The KCl-induced constrictions observed after 120 min were statistically higher (p < 0.05)
when preparations were challenged three times (30 min, 60 min, 120 min), compared to those challenged only once. The preparations that were stored at 4 ⁰C for
24 h showed significantly stronger serotonin-induced constrictions (p < 0.01). The
cold storage had no influence on KCl-induced constriction.
Conclusion: For performing in vitro studies on HUA preparations in tissue bath, we
propose stretching tension of 2.0 g, incubation period of 120 min and multiple initial constriction challenging with KCl as optimal experimental condition. We also
showed that HUA preparations retained functional viability even after 24 h of cold
storage.
