Table 1.

NH₄Cl dose-dependent uptake and release of ammonium, glucose, and lactate by mixed cell aggregate cultures

NH4Cl (mm)	Days 5–8		Days 8–11		Days 11–13
		p		p		p
	Ammonium
0	−26  ± 1		−4  ± 1		−2  ± 1
1.0	−55  ± 13	<0.001	−31  ± 4	<0.001	−38  ± 1	<0.001
2.5	−113  ± 19	<0.001	−96  ± 2	<0.001	−114  ± 1	<0.001
5.0	−176  ± 16	<0.001	−250  ± 2	<0.001	−264  ± 10	<0.001
	Glucose
0	−399  ± 19		−464  ± 12		−756  ± 4
1.0	−372  ± 32	NS	−389  ± 22	<0.01	−656  ± 48	<0.05
2.5	−525  ± 32	<0.01	−468  ± 7	NS	−835  ± 17	<0.01
5.0	−672  ± 21	<0.001	−623  ± 19	<0.001	−1026  ± 7	<0.001
	Lactate
0	137  ± 5		166  ± 6		685  ± 26
1.0	152  ± 18	NS	149  ± 39	NS	549  ± 21	<0.01
2.5	269  ± 22	<0.001	153  ± 22	NS	696  ± 73	NS
5.0	431  ± 34	<0.001	370  ± 41	<0.001	1137  ± 22	<0.001

Net uptake (net decrease in culture medium) and release (net increase in culture medium) by aggregates, calculated from days 5–8, 8–11, and 11–13 are expressed as nanomoles per hour per milligram of protein. Measures were taken at days 5 (start of treatment), 8 (before and after medium change), 11 (before and after medium change), and 13 (end of treatment). Proteins were measured at day 13. Data are means ± SD of three separate cultures. Statistical pvalues are shown (Student's t test) for comparison with controls (NH₄Cl = 0 mm); NS, not significant.