IV. BIOCHEMICAL SYSTEMS 



349 



It is to be expected that more work of this nature with })acterial prepara- 

 tions will help ekicidate tlie pathway by which animals metabolize myo- 

 inositol. It is ah-eady apparent that, if the pathway in animal tissues is 

 similar to that shown above, the formation of pyruvate or lactate would 

 be an adequate explanation of the antiketogenic effect of inositol and of 

 the conversion of stably bound deuterium in inositol to stably bound 

 deuterium in urinary glucose (see below) . 



8 15 24 



Hours after dosing 

 Fig. 1. Rate of inositol absorption in fasted rats.'' 



2. In Animals 



a. Absorption 



m?/o-Inositol is absorbed from the digestive tract of animals but at a 

 relatively slow rate compared with glucose. Figure 1 (from Wiebelhaus 

 et al?'^) shows the rate of absorption of approximately 280-mg. doses of 

 w2/o-inositol administered by stomach tube to rats of approximately 200-g. 

 body weight. The rate of absorption was measured by quantitative deter- 

 minations'^ of the inositol remaining in the gastrointestinal tract. A com- 

 parison of the assay values for the hydrolyzed and unhydrolyzed samples 

 indicated that no conversion of administered inositol to a bound form had 

 occurred in the intestine. However, about one-half of the 8 to 12 mg. of 

 inositol present in the tract of fasted animals (or of the experimental ani- 



" R. E. Franzl and E. Chargaff, Federation Proc. 9, 173 (1950). 



" R. E. Franzl and E. Chargaff, Nature 168, 955 (1951). 



" B. Magasanik, J. Am. Chem. Soc. 73, 5919 (1951). 



" V. D. Wiebelhaus, J. J. Betheil, and H. A. Lardy, Arch. Biochem. 13, 379 (1947). 



