In a perfect world, DiMassimo said, "we would all sit down, and have a totally objective, rational, cerebral exchange where we just hash through the things that matter.
Cerebral net exchange different from 0, * P < 0.05; ** P < 0.01.
Hence, further studies are needed to understand how vascular pathology affects cerebral water exchange.
Systemic inflammation may affect brain function by reducing the BCAA/AAA ratio, thereby changing the cerebral net exchange of LNAAs.
Therefore, we cannot conclusively state that no changes in the cerebral net exchange of ammonia were induced by LPS infusion.
In addition, glucose uptake, cerebral lactate exchange, OGI, and OCI remained unchanged, and the cerebral respiratory quotient (∼1.03) was stable (8).
Based on the methods and findings in the present study, we cannot definitively conclude that the cerebral net exchange of a given amino acid is unaffected in sepsis.
Because we did not detect any changes in the cerebral net exchange of phenylalanine, our findings furthermore imply that a new steady state, with elevated phenylalanine levels in the cerebral interstitial fluid, had been established before the second measurement [ 23].
An unchanged cerebral net exchange could furthermore involve changes in BBB function per se through a compensatory increase in the unidirectional cerebral efflux of phenylalanine, a parameter that was not assessed in the present study.
At present, neither the physiological implications of alterations in the BCAA/AAA ratio nor the effects of systemic inflammation on the cerebral net exchange of LNAAs has been investigated in humans.
The cerebral net exchange of ammonia did not differ from 0 at any time and was unaffected by LPS infusion (baseline, 139 ([-70] - 348) nmol/100 g/min; LPS, -98 ([-618] - 422) nmol/100 g/min; NS).
