Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Feasibility of using radiolabeled nitrogen-13 to track nitrogen kinetics in rodents exposed to hyperoxia or hyperbaric pressure
Ist Teil von
Physiology (Bethesda, Md.), 2023-05, Vol.38 (S1)
Erscheinungsjahr
2023
Link zum Volltext
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
Abstract only
Decompression sickness occurs from tissue supersaturation with nitrogen when pressure is reduced. It limits operational capacity in diving, aviation and extravehicular activity in space. Little is known about organ variability, and why differences exist between individuals. Procedures are based on empirical testing and mathematical modelling, with limited data from actual nitrogen load or diffusivity. Nitrogen has a positron-emitting isotope that can be made in gaseous form (
13
N
2
) which can then be monitored spatially and temporally. The feasibility to study nitrogen kinetics was assessed using hyperbaric pressure to increase the partial pressure or pre-breathing oxygen to increase tissue uptake capacity, both of which would expect to cause increased nitrogen uptake. Fifteen female Sprague Dawley rats were divided into air-breathing normobaric (CON), oxygen-breathing, including 1 h pre-breathing (OXY), and air-breathing hyperbaric, compressed to 700 kPa (HB). Breathing gases were supplemented with trace amounts of
13
N
2
for 30 min, with CON & OXY euthanized at 30 min. HB were decompressed and breathed air/isoflurane without
13
N
2
for 10-15 minutes before euthanized. Blood, liver, brain, femur (bone) and thigh muscle were analyzed in a gamma counter with the
13
N
2
counts normalized for organ mass. In liver (p=.026) and brain (p=.018)
13
N
2
was greater in OXY than both CON and HB. In the femur HB was higher than CON (p=.048). Results suggest that pre‑breathing O2 in OXY removed tissue nitrogen creating a larger gradient for
13
N
2
uptake. We interpret the limited increase in
13
N
2
in HB was due to off-gassing in high-perfused tissues during decompression, with the high femur value being due to uptake in HB but slower off-gassing during decompression. Our data suggest that
13
N
2
can be used to track gas kinetics in a live rodent during physiological conditions endured by humans.
This study was supported by a grant from the Office of Naval Research.
This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.