1 research outputs found
Synchrotron XRF and Histological Analyses Identify Damage to Digestive Tract of Uranium NP-Exposed Daphnia magna
Micro- and nanoscopic X-ray techniques were used to investigate
the relationship between uranium (U) tissue distributions and adverse
effects to the digestive tract of aquatic model organism Daphnia magna following uranium nanoparticle (UNP)
exposure. X-ray absorption computed tomography measurements of intact
daphnids exposed to sublethal concentrations of UNPs or a U reference
solution (URef) showed adverse morphological changes to
the midgut and the hepatic ceca. Histological analyses of exposed
organisms revealed a high proportion of abnormal and irregularly shaped
intestinal epithelial cells. Disruption of the hepatic ceca and midgut
epithelial tissues implied digestive functions and intestinal barriers
were compromised. Synchrotron-based micro X-ray fluorescence (XRF)
elemental mapping identified U co-localized with morphological changes,
with substantial accumulation of U in the lumen as well as in the
epithelial tissues. Utilizing high-resolution nano-XRF, 400–1000
nm sized U particulates could be identified throughout the midgut
and within hepatic ceca cells, coinciding with tissue damages. The
results highlight disruption of intestinal function as an important
mode of action of acute U toxicity in D. magna and that midgut epithelial cells as well as the hepatic ceca are
key target organs