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STEADY STATE MAINTENANCE OF ELECTROLYTES IN THE SPINAL CORD OF THE FROG
Author(s) -
Bianchi C. Paul,
Erulkar S. D.
Publication year - 1979
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1979.tb02278.x
Subject(s) - sodium , chemistry , choline chloride , spinal cord , electrolyte , sucrose , lithium chloride , potassium , nuclear chemistry , calcium , isotopes of sodium , chloride , magnesium , zoology , chromatography , biochemistry , inorganic chemistry , biology , organic chemistry , electrode , neuroscience
Isolated frog spinal cords equilibrated from 3 to 24 h in Ringer's solution maintained steady state conditions with regard to electrolyte composition. Total sodium and chloride contents measured on the same spinal cords were found to be nearly equivalent (Na = 46.6 ± 1.4μmol/g wet wt vs Cl = 46.2 ± 1.2μmol/g wet wt). Calcium and magnesium contents were 3.0 ± 0.5 and 4.8 ± 0.2pμol/g wet wt respectively for fresh spinal cords and 2.1 ± 0.4 and 5.5 ± 0.9pmol/g wet wt respectively for spinal cords equilibrated for 24 h. Zinc content was 0.29 ± 0.01 μmol/g wet wt. Insulin space was found to be smaller than sucrose space (0.24 ml/g vs 0.37 ml/g). Sodium and chloride spaces were slightly higher than sucrose space. Sodium and chloride in the non‐sucrose space was 4.8 and 9.5 μmol/g wet wt. Residual radioactive sodium, or sodium content of spinal cords washed out for 180 min in non‐radioactive Ringer's solution or in choline or lithium Ringer's solution, was 4.2 ± 0.4μmol/g wet wt (n = 9). The agreement between residual sodium content and sodium in the non‐sucrose space suggests that the mean intracellular sodium content of the spinal cord neurons is low.