STUDIES ON NERVE METABOLISM

Abstract

Fresh sciatics of winter Rana pipiens contain 27 mgm. % total soluble P, summer R. pipiens 39 mgm. %, spring R. temporaria 24 mgm. %, rabbit 25 mgm. %. For frog nerve this is present, roughly, 1/2 in inorganic form and 1/4 each in acid labile and acid stable combination. For rabbit nerve, nearly 1/2 is in stable combination. Rest in O leads to a slight increase of combined P at expense of the inorganic. Rest in N causes breakdown of a good portion of both combined fractions so that the inorganic fraction constitutes 70% of the total, the others 15% each. Rest in O following N restores the initial ratios. Tetaniza-tion in O has an effect like asphyxia, giving 60% in-organic and 20% of each bound fraction. The total soluble P increases 5-10% during rest in O for several hrs. and about 15% in N or on stimulation. This may result from the breakdown of phosphatids. The results are considered in relation to carbohydrate metabolism and equilibration in nerve.