332 



M. WOODS, K. WIGHT, J. HUNTER, D. BURK 



VOL. 12 (1953) 



with brain slices in Hank-Simms medium the average control Qq^^ was 2.4 (range 2.0 

 to 3.15) and the addition (before placing vessels at 38° C) of 0.4 mg of phenol per ml 



raised the (^co, ^^ 5-25 (range 4.60 to 6.45). 

 x\ddition of a commercial insulin prepara- 

 tion to give an equivalent concentration of 

 phenol raised the 0^5, to a similar level, 

 i.e. average5.09(range4.7to6.o).In the ab- 

 sence of phenol, increasing the magnesium 

 level from o.oi mg to 0.4 mg per ml in three 

 typical experiments increased the Qq^^ an 

 average of 200 % (range 131 to 268 %) . With 

 the same preparations, an identical in- 

 crease in magnesium level in the presence 

 of 0.4 mg phenol per ml, gave an average 



Fig. I . Influence of magnesium level and phenol 

 plus insulin (= commercial insulin) on rates of 

 anaerobic acid production (solid lines) by mouse 

 brain slices in Hank-Simms solution plus 0.03 M 

 KHCO3 and 0.625 % dextrose. B, with phenol, 

 0.4 mg and insulin, 4 units per ml (= commercial 

 insulin) ; A, control minus phenol and insulin. The 

 rate of decay in acid production (dotted line) is 

 represented by the 0^6, obtained for the period o 

 to 66 minutes divided by the (?c6., ^o^ the period 

 66 to 152 minutes. Gas phase 95% Ng^-^^S/o COg. 



0.3 04 0.5 



Milligrams magnesium per cc 



Brain 



Anaerobic Glycotysis 



Extra Magnesium 

 <S Phenol 



'Extra Magnesium 



,-PAieno/ 



^■Zn-lnsulin & Phenol 

 ICommercial Insulin) 



.^Cryst.Zn- insulin 

 ^—Control 



60 Minutes 



Fig. 2. The influence of crystalline zinc-insulin (4 units per ml), phenol (0.4 mg per ml), commercial 

 regular insulin (4 units crystalline zinc-insulin and 0.4 mg phenol per ml), extra magnesium (0.48 mg 

 magnesium per ml), and phenol plus extra magnesium (same respective concentrations) on rate of 

 anaerobic acid ])roduction in brain (100 mg wet wt. of slices). Control level of magnesium = 0.016 

 mg per ml. In all cases Hank-Simms solution with 0.03 M KHCO3, and 0.625% dextrose. Gas phase 



95% N2 and 5% CO2. 



References p. 346. 



