I. A radiometric micro-volume procedure for measurement of erythrocytic hexose monophosphate shunt (HMS) activity in intact cells in vitro is described.
2.The procedure is rapid, allowing 200 individual HMS determinations in a single experiment of 5 hr duration.
3. The procedure is reproducible, yielding HMS activity means insignificantly different (P \u3e 0.05) between replicate experiments.
4. A profile of sodium nitrite-induced HMS stimulation is reported: HMS was elevated 2-fold (P \u3c 0.001) between zero and 2.5mM NaN02; HMS elevation was more distinct (7-fold) between 2.5 and 5.0mM NaNO2; maximum activity (22-fold) was observed between 10 and 20mM NaN02; \u3e 20mM NaNO2 caused significant (P \u3c 0.001) diminution of HMS; glucose carbon recycling through the HMS occurred only with \u3e 2.5mM NaNO2 where this process contributed :::; 16% to total HMS activity
