Intracellular sodium content of a wall-less strain of Neurospora crassa and effects of insulin: a 23Na-NMR study.
23Na-NMR has been used to investigate some factors influencing the sodium content of a wall-less strains of Neurospora crassa. The shift reagent Tm(DOTP)H2(NH4)3 proved useful for this purpose, while several other reagents, previously used by others, were found to be unsuitable for use with these cells. When the cells were grown, washed and resuspended in medium containing sodium (25.3 mM), the intracellular sodium concentration was calculated to be 11.9 +/- 1.4 mM. This value rose within two minutes of addition of glucose (100 mM), to greater than 14 mM. Preincubation of cells with insulin (100 nM) had a significant effect on the subsequent rate of sodium accumulation during the period 3-12 minutes following glucose addition. Insulin-treated cells showed a slow, continued accumulation of sodium during this period (+1.14 +/- 0.39%/min), while control cells lost sodium very slowly (-0.63 +/- 0.29%/min; P of difference = 0.005).
Greenfield
N J
NJ
Department of Physiology and Biophysics, UMDNJ-Robert Wood Johnson Medical School (at Rutgers), Piscataway 08854-5635.
Cherapak
C N
CN
Adebodun
F
F
Jordan
F
F
Lenard
J
J
D005947:Glucose / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D009491:Neurospora / Q000378:metabolism*; D009492:Neurospora crassa / Q000187:drug effects / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*
D007328:Insulin; D012964:Sodium; D005947:Glucose