Creatine in nerve, muscle and brain

Abstract

ONE FIGUKEEarlier experiments on soluble phosphates in frog nerve (Gerard and Wallen, '29) showed the presence of a fraction, 'labile phosphate,' closely resembling in behavior the phosphagen or creatine-phosphate of muscle. A similar arginine-phosphate fraction has been studied in invertebrate nerve (Tang, Tang and Gerard, '32 ; Engel and Gerard, '35). The more complete identification of the nerve substance could be achieved by actual isolation, a rather thankless task when but a few milligrams of nerve are available per frog; or, for practical demands, by demonstrating a bound creatine fraction paralleling in stochiometric fashion the labile phosphate. The second procedure offered further opportunity of rechecking, by following changes in creatine, many of the conclusions drawn from the phosphate study. This alternative was chosen, and, as the work progressed, it became clear that we were in fact dealing with creatine-phosphate as one of the creatine fractions. Many additional data have been obtained as to its behavior under various treatments of nerve; and parallel studies with muscle have yielded similar but often distinctive results. Incidentally, interesting information concerning another chromogenic fraction has accumulated, especially from analysis of brain. METHODS 1.Tissue. Nerves were dissected, with the usual precautions, into iced mortars. Unless in experimental solutions, they remained in moist gas (to obviate diffusional losses) usually hung from platinum electrodes 'Aided by a grant from the Rockefeller Foundation t o The Uiiiversity of Chicago. Summary reports of part of this work have appeared in: Proc. Soe.

Phosphorus metabolism of intact crab nerve and its relation to the active transport of ions.

“…Basically similar results to the present ones were obtained by Gerard & Tupikova (1938, 1939. They observed that during stimulation of sciatic nerve the Pi content was elevated.…”

Effects of Potassium, Sodium, and Azide on the Ionic Movements That Accompany Activity in Frog Nerves

“…The energy reserve represented by creatlne phosphate and ATP may be computed to be 0.19 cal./gm, dry, if one uses the estimates of Gerard and Tupikova (1938) and Greengard et al (1954) for the nerve content of these substances and employs the previous figure for the free energy of hydrolysis of the terminal phosphate bonds of these compounds.…”

Effects of Azide and Chloretone on the Sodium and Potassium Contents and the Respiration of Frog Sciatic Nerves

“…It can be seen that the free energy required to transport sodium and potassium ions comprises approximately 10 per cent of that available from the metabolism in oxygen and about one-third of that II Calculated assuming free energy of hydrolysis of the terminal phosphate group of ATP and creatine phosphate to be -8 kcal./mole (Kitzinger et od., 1957). ¶ Gerard and Tupikova (1938). **Greengard, Brink, and Colowick (1954).…”