1 research outputs found
Development and Application of a Low-Volume Flow System for Solution-State <i>in Vivo</i> NMR
<i>In vivo</i> nuclear magnetic resonance (NMR) spectroscopy
is a particularly powerful technique, since it allows samples to be
analyzed in their natural, unaltered state, criteria paramount for
living organisms. In this study, a novel continuous low-volume flow
system, suitable for <i>in vivo</i> NMR metabolomics studies,
is demonstrated. The system allows improved locking, shimming, and
water suppression, as well as allowing the use of trace amounts of
expensive toxic contaminants or low volumes of precious natural environmental
samples as stressors. The use of a double pump design with a sump
slurry pump return allows algal food suspensions to be continually
supplied without the need for filters, eliminating the possibility
of clogging and leaks. Using the flow system, the living organism
can be kept alive without stress indefinitely. To evaluate the feasibility
and applicability of the flow system, changes in the metabolite profile
of <sup>13</sup>C enriched <i>Daphnia magna</i> over a 24-h
period are compared when feeding laboratory food vs exposing them
to a natural algal bloom sample. Clear metabolic changes are observed
over a range of metabolites including carbohydrates, lipids, amino
acids, and a nucleotide demonstrating <i>in vivo</i> NMR
as a powerful tool to monitor environmental stress. The particular
bloom used here was low in microcystins, and the metabolic stress
impacts are consistent with the bloom being a poor food source forcing
the <i>Daphnia</i> to utilize their own energy reserves