Plasma or hormones added to hepatocyte incubation media mask the function of membranes as substrata per se for hepatocyte adhesion. This hypothesis was verified with hepatocyte cultures on various membranes in serum and hormone free medium. Freshly isolated rat hepatocytes were seeded on flat sheet membranes made of Cellulose Acetate (CA), aminated Cellulose Acetate (aCA), polysulfone (PSf) and sulfonated polysulfone (sPSf) and incubated in Hank's Balanced Salts Solutions (HBSS) as well as in William's E medium supplemented with newborn calf serum. It was found that PSf promoted hepatocyte adhesion most effectively. Good properties of PSf as a biomaterial for hepatocyte culture were confirmed in both media cultures. Urea synthesis and ammonia utilization measured in hepatocytes cultured on PSf were higher compared with other membrane cultures. PSf secured longer viability for a higher number of cells seeded on membrane compared with other investigated membranes, which is the reason for higher metabolic activity in PSf culture.

Flavonoid supplementation is likely to be beneficial in improving rumen fermentation and in reducing the incidence of rumen acidosis and bloat. Flavonoids are also said to increase the metabolic performance during the peripartum period. Ruminants are constantly exposed to flavonoids present in feed. However, it is not clear if these phytochemicals can affect the activity of the gut smooth muscle. Therefore, the aim of the study was to verify the effect of three flavonoids on bovine isolated abomasum smooth muscle. The study was carried out on bovine isolated circular and longitudinal abomasal smooth muscle specimens. All experiments were conducted under isometric conditions. The effect of apigenin, luteolin and quercetin (0.001 to 100 M) dose-dependently showed myorelaxation effects. Luteolin and quercetin applied in low doses increased the force of the ACh-evoked reaction. However, if used in high doses in experiments testing a wide range of concentrations, their contractile effect either declined (luteolin) or was replaced by an antispasmodic effect (quercetin). Surprisingly, the reaction induced by flavonoids after repeated exposure to the same phytochemical was not reproducible in experiments testing only single exposure of abomasum strips to the same flavonoid used in a high concentration. Taking into account the physicochemical properties of flavonoids, this data suggests the ability of flavonoids to interfere with cell membranes and, subsequently, to modify their responsiveness. Assuming ruminant supplementation with luteolin or quercetin or their presence in daily pasture, a reduction of the likelihood of abomasum dysmotility should be expected.