Intracellular Ca2+ regulation in hepatocytes under experimental transplantation conditions.

Under transplant conditions excessive accumulation of intracellular calcium ([Ca2+](i)) is considered to be a mediator of cell injury during ischaemia and re-oxygenation. To clarify this consideration as well as the necessity of calcium-free preservation solutions, we used a well-known in-vitro model. Furthermore, a new application to mimic clinical situation was established, and we evaluated the correlation between [Ca2+](i) change and cell survival in monolayers of isolated rat hepatocytes undergoing cold hypoxia in defined solutions and during re-oxygenation.

Human duodenal spheroids for noninvasive intracellular pH measurement and quantification of regulation mechanisms under physiological conditions.

Three-dimensional cell cultures (spheroids) of biopsies of human duodenum were used to develop a new noninvasive method for studying intercellular and intracellular mechanisms. Through examinations of intracellular pH regulation, high functional similarity to native tissue could be shown, as already evidenced morphologically. A special microperfusion chamber was developed to fix individual spheroids physically to a nylon net, via laminar perfusion flow through the chamber.