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Influence of Hypoxia on Acute Lead Toxicity and Calcium Homeostasis in Early Life Stage Zebrafish (Danio rerio)

The purpose of this study was to investigate the effects of Pb and hypoxia co-exposure on Pb toxicity and Ca homeostasis in early life stage (ELS) zebrafish (Danio rerio). Previous evidence indicates that exposure of ELS zebrafish to hypoxia (~20% air saturation) reduces Ca uptake, likely through down-regulation of the apical epithelial Ca channel (ECaC). Considering that Pb and Ca are known antagonists and compete for uptake pathways, it was hypothesized that co-exposure of Pb with hypoxia would decrease Pb toxicity by reducing Pb uptake (likely mediated through a reduced number of ECaCs). However, it was shown that at 96 hpf, whole body accumulation of both Pb and Ca was lower at 40% air saturation compared to 100% and 20% air saturation. This result closely aligned with the 96h LC50 results which showed the highest mortality of zebrafish at 40% compared to the other air saturation levels. This suggests that toxicity is likely the result of exacerbated hypocalcemia at 40% air saturation due to both Pb competition for Ca binding to Ca uptake channels/transporters, such as ECaC, and potentially reduced expression of such channels/transporters in response to this level of hypoxia. Overall, it appears that ELS zebrafish respond differentially to …
Date: December 2021
Creator: Moghimi, Mehrnaz
System: The UNT Digital Library

Reduced Visceral Fat and Biological Indices of Inflammation Following Combined Prebiotic/Probiotic Supplementation in Free Living Adults

Probiotics/prebiotic supplementation represents a viable option for addressing systemic inflammation and chronic disease risk resulting from excessive body weight. The purpose of this feasibility study was to determine if 90-d of supplementation with prebiotic and probiotic could alter mRNA responsible for inflammation and subsequently metabolic health in weight stable overweight adults. Participants were advised to not change their diet or exercise habits during the study. All protocols were approved by the University IRB and participants gave written informed consent. Participants were randomly assigned to either placebo (N=7; rice flour) or combined (N=8) prebiotic (PreticX® Xylooligosaccharide; 0.8 g/d; ADIP) and probiotic (MegaDuo® Bacillus subtilis HU58 and Bacillus coagulans SC-208; 3 Billion CFU/d) and measurements were made at baseline, 30, 60, and 90-d. Whole body DXA scans (GE iDXA®) and blood 574-plex mRNA analysis (Nanostring®) were used to generate primary outcomes. Compared to placebo, supplementation was associated with a 36% reduction in visceral adipose tissue (p = 0.001). Supplement resulted in significant, differential expression of 15 mRNA associated with adipose tissue inflammation, systemic inflammation, and/or chronic disease risk. The key findings support that 90-d prebiotic/probiotic supplementation may be associated with an improved metabolic health, reduced adipose tissue inflammation, reduced systemic inflammation, and …
Date: December 2021
Creator: Tanner, Elizabeth A.
System: The UNT Digital Library