Changes in intracellular water diffusion and energetic metabolism in response to ischemia in perfused C6 rat glioma cells

Abstract

This work reports results of experiments in hollow-fiber bioreactor C6 glioma cell cultures where the apparent diffusion coefficient (ADC) of intracellular water (iADC) was measured at diffusion times between 0.83 and 40 ms. The experiments were carried out before and after the onset of permanent ischemia. The changes in iADC following ischemia were dependent on the diffusion time employed in the experiment. An ischemia-induced decrease in the iADC was measured at short diffusion times, while at long diffusion times the iADC increased. Decreases in the iADC measured at short diffusion times are interpreted to be a result of a decrease in the intrinsic diffusivity of intracellular water due to energy failure. Increases in iADC measured at long diffusion times, are interpreted to result from cell swelling.

An improved model for prostate diffusion incorporating the results of Monte Carlo simulations of diffusion in the cellular compartment

“…Similarly, we assumed for simplicity that intra‐ and extracellular values of D free are equal. Although this has been assumed previously, others have suggested that extracellular diffusion coefficient values are greater than intracellular ones . Fifth, we have assumed that cell wall permeability is unchanged in cancer.…”

“…D free of intra‐cellular fluid has been measured to be 2 μm 2 ms −1 in HeLa cells at 37°C, and to be 1.7–2.5 μm 2 ms −1 in both pre‐ and post‐ischemic C6 perfused rat glioma cells . D free may be different intracellularly than extracellularly due to differences in protein concentration and thus increases in dynamic viscosity.…”

“…D free may be different intracellularly than extracellularly due to differences in protein concentration and thus increases in dynamic viscosity. However, it has also been estimated that extracellular D free is not significantly different . In this study, it was assumed that intra‐ and extracellular values of D free were equal, with a value of 1.7 μm 2 ms −1 .…”

Translational MR Neuroimaging of Stroke and Recovery

“…However, the precise temporal order and relative magnitude of the biological mechanisms contributing to ADC remain controversial. On a very rapid time scale of minutes following complete cessation of flow, initial changes in ADC reflect processes that are potentially reversible, including energy-dependent processes like cytoplasmic streaming [38] or cell swelling secondary to acidosis [39]. When ATP falls below a critical threshold of about 30% [40], membrane sodium and potassium pumps become impaired, and anoxic depolarization produces cellular swelling.…”

Evaluation of the NMR-MOUSE as a new method for continuous functional monitoring of the small intestine during different perfusion states in a porcine model

“…The literature regarding the interpretation of the two diffusion components is controversial, but the fast diffusion component can be understood to refer to the water in the intracellular compartment whereas the slow diffusion component refers to water in the extracellular or interstitial compartment [ 22 ]. However, it has been questioned whether the two compartments can be assessed separately in vivo [ 23 ]. As to the FC in the present study, its tendency to decrease during flow reduction could be explained by a reduced cellular metabolic activity due to the lack of available energy.…”