Determination of bone sodium (Na) and Na exchange in pig leg using in vivo neutron activation analysis (IVNAA)

Abstract

Objective: The locations of sodium (Na) storage and its exchange mechanisms in the body are not well known. Understanding tissue Na storage and exchange is important for understanding the impact of Na intake, absorption, and retention on human health, especially on the risk of developing chronic diseases. The purpose of this study was to investigate the application of a deuterium-deuterium (DD) neutron generator-based IVNAA system in Na nutrition studies. Approach: The right legs of two live pigs, one on a low Na diet and one on a high Na diet, both for 14 d, were irradiated inside a customized irradiation cave for 10 min (45 mSv dose to the leg) and then measured with a 100% efficient high purity germanium detector (HPGe). The spectra were analyzed to obtain the net Na counts at different time points. Bone Na concentrations were calculated using the calibration created with Na bone phantoms. Main results: The results show that the difference in bone Na to calcium between the pigs on high versus low Na diets was 466 ± 137 ppm. The estimated bone Na to calcium concentrations were 1166 ± 80 and 1631 ± 111 ppm for low and high Na diet pigs, respectively. Analysis also shows rapid exchange of Na in the leg during the first 2 h measurements, while the exchange was minimal at the second and third 2 h measurements, taken 7 and 21 h post irradiation. The exchange decay time of Na in the leg was 51 min for the first measurement, and there was no significant change of Na activities between 2-21 h. Significance: With these results, we conclude there is a non or low exchangeable compartment (likely to be bone) for Na storage and that DD neutron generator-based IVNAA is a useful method for determining tissue Na distribution in nutrition studies.

Determine Sodium in Bone and Bio-Kinetics of Sodium in Pig Model by Using In Vivo Neutron Activation Analysis

“…the absolute concentrations from in vivo measurement may be problematic however the concentrations can still be used for relative comparison). Also, the agrement between in vivo and ex vivo measurement has improved 2 times as compared with our previous study where we found ex vivo measurements to be four times higher primarily due to phantom calibration line 16 . More studies with large sample size are required to confirm the methodology's efficacy for in vivo bone sodium measurement.…”

“…The student's t-test at 5% level showed no significant difference in bone sodium of low-sodium and high-sodium diet pigs after 14 days of dietary sodium intervention. In our previous pig study we found Na/Ca bone concentration of 1165 ± 80 ppm in low sodium diet pig while the high sodium diet pig estimated to have a Na/Ca concentration of 1631 ± 111 ppm 16 . The ex-vivo bone sodium concentrations for pig L and pig H were calculated to be 1870(±11) ppm and 2029(±6) ppm.…”

“…However, besides skin and muscle as a sodium storage compartment, a radiosodium dilution study proposed that sodium might be stored in the bone 15 .The in vivo bone sodium deposition studies are lacking, mainly due to the lack of in vivo sodium measurement techniques. Earlier, our group performed experiments on pigs and published the preliminary results for the in vivo sodium 16 . However, we observed a large difference between in vivo and ex vivo bone sodium.…”

Analysis of the Chemical Composition and Morphological Characterization of Tissue Osseointegrated to a Dental Implant after 5 Years of Function

“…Finally, Na was also present in the bone tissue in a smaller proportion. It has been shown that among the biological functions of bone tissue is the deposit of minerals, where sodium residing in bone tissue stands out [ 37 , 38 ].…”