Napapon Sailasuta1, Brian D. Ross1,2
1Clinical MR Spectroscopy, Huntington
Medical Research Institutes, Pasadena, CA, United States; 2Rudi
Schulte Research Institute, Santa Barbara , CA, United States
Human
brain pH is a significant clinical measure usually accomplished directly
through implantable pH electrodes, or indirectly from HCO and C02 together
with Henderson-Hesselbach tables. In
recent 13C MRS studies we were able to directly quantify bicarbonate in
resting human brain and to monitor the changes produced by short or long term
fasting. pH estimated from 13C HC03
differed significantly from accepted normal values and those obtained by
direct 31P MRS. Possible confounds,
including binding, compartmentation and T1/T2 variances are considered before
concluding that human brain [bicarbonate] is lower than previously thought.