BIOCHEMICAL PROPERTIES OF SQUID AXON MEMBRANES.
Annual rept. no. 1,
CHILE UNIV SANTIAGO LABORATORIO DE BIOFISICA
Pagination or Media Count:
Biochemical and physiological studies in the giant axons of the Chilean squid Dosidicus Gigas were carried out in order to correlate metabolic dependent sodium transport and the enzymic profile of nerve membranes. Membrane fractions were isolated from the sheath of giant fibers by means of differential centrifugations and its ATP splitting system was studied as a function of pH, cations, anions composition of the media, as well as the effect of ouabain, and the excess of substrate. Evidence accumulated by these studies indicate that the velocity of the enzyme reaction is dependent on the hydration of the cation, the hydration of the anion and is dependent on the charge of the enzyme particle at different pH values. Na-22 efflux from intact axons was almost completely inhibited by 0.00001 M ouabain. Intraplasmic microinjection of ATP did not recovered sodium transport of ouabain-inhibited nerves, as cyanide-treated one occurred. Microinjection of ATP to normal axons inhibited sodium transport, probably because the excess of substrate inhibited the ATP splitting system of the isolated membrane fractions. Author
- Anatomy and Physiology