Table 2.

Effect of dithiothreitol and nitric oxide donors on Lucifer yellow-labeled area.

Culture batch	Culture condition	Lucifer yellow-labeled area (μm2)	Percent
1	Low Glucose	20,110 ± 8,302 (n=11)	100
	High Glucose	5,303 ± 4,810 (n=17)*	26
	High Glucose + dithiothreitol	21,103 ± 7,776 (n=21)	105
2	Low Glucose	12,907 ± 6,718 (n=22)	100
	Low Glucose + nitroprusside	4,573 ± 3,557 (n=27)**	35
3	Low Glucose	5,581 ± 3,463 (n=44)	100
	Low Glucose + spermine-NO	2,947 ± 1,380 (n=28)**	53

Separate batches of astrocytes were grown for 2 weeks in low (5.5 mmol/L) or high (25 mmol/L) glucose. Lucifer yellow-labeled area was assayed on day 14 by impaling a single cell with a micropipette containing 4% Lucifer yellow VS (62 mmol/L) and allowing the dye to diffuse for 2 min (see Fig. 6). Immediately prior to the dye transfer assay, high glucose cultures were treated with vehicle or dithiothreitol (DTT; 10 mmol/L) for 10 min. Separate batches of low glucose cultures were treated with vehicle and either sodium nitroprusside (200 μmol/L) or spermine-NO (250 μmol/L). The vehicle and nitric oxide donors were added to the culture medium and cells were returned to the CO₂ incubator for 1h prior to the dye-transfer assay. Values are means ± SD for the number of samples indicated.

^*, p<0.001 vs. DTT or 5.5 mM glucose, ANOVA and Bonferroni test;

^**, p<0.001 vs. respective control group, t test.