Table 1.

Elemental concentrations in subcellular compartments of frog sympathetic ganglion neurons

	n	Na	Mg	P	K	Ca
		(mmol/kg dry weight)
Mitochondria
Control	107	11  ± 2	21  ± 1	380  ± 7	347  ± 6	−0.4  ± 0.2***
Depolarization
50 mm K+, 45 sec	77	27  ± 2**	19  ± 1	384  ± 13	308  ± 10	13.0  ± 1.5**
50 mm K+, 45 sec + FCCP	28	10  ± 1	12  ± 1	327  ± 14	251  ± 15	0.6  ± 0.7***
50 mm K+, 2 min	114	34  ± 1**	27  ± 2	364  ± 9	285  ± 8	32.7  ± 5.1**
30 mm K+, 45 sec	113	17  ± 2*	20  ± 1	350  ± 6	344  ± 9	3.0  ± 0.4**
30 mm K+, 2 min	111	31  ± 2**	22  ± 1	417  ± 9	363  ± 8	12.8  ± 2.5*
Recovery from 50 mmK+, 2 min
2 min	106	26  ± 2**	20  ± 1	380  ± 6	397  ± 12	4.7  ± 1.2**
5 min	93	13  ± 2	18  ± 1	349  ± 5	312  ± 6	0.8  ± 0.4
15 min	69	10  ± 2	26  ± 2	387  ± 7	330  ± 10	1.4  ± 0.5
Cytoplasm
Control	59	31  ± 5	47  ± 3	470  ± 32	950  ± 50	3.3  ± 1.0
Depolarization
50 mm K+, 45 sec	81	37  ± 2	33  ± 2	456  ± 22	739  ± 37	7.3  ± 1.1**
50 mm K+, 45 sec + FCCP	31	20  ± 2*	39  ± 3	479  ± 28	736  ± 44	6.9  ± 1.5*
50 mm K+, 2 min	67	42  ± 4	38  ± 3	376  ± 21	558  ± 35	7.0  ± 1.2*
30 mm K+, 45 sec	116	43  ± 6	33  ± 1	419  ± 14	779  ± 16	6.6  ± 0.9*
30 mm K+, 2 min	47	42  ± 5	47  ± 4	491  ± 34	825  ± 47	6.7  ± 2.2
Recovery from 50 mm K+, 2 min
2 min	128	40  ± 3	42  ± 3	506  ± 15	852  ± 21	5.5  ± 0.7*
5 min	94	23  ± 3	36  ± 2	514  ± 16	815  ± 24	5.6  ± 1.2
15 min	28	23  ± 5	53  ± 5	580  ± 34	888  ± 42	5.4  ± 1.4

Data are given as mean ± SEM, where column n is the number of mitochondria or cytoplasmic regions analyzed. The number of neurons analyzed was 8–18 per experimental condition taken from three to four ganglion (except for 15 min Recovery, which represents measurements from two ganglia). Concentrations were also obtained for S and Cl (range 100–150 mmol/kg dry weight for S and 100–200 and 30–60 mmol/kg for Cl in cytoplasm and mitochondria, respectively). For these elements, there were no significant concentration differences between locations or conditions. Concentrations are given in units of mmol/kg dry weight; conversion to mmol/l H₂O-accessible volume is described in Materials and Methods.

*Significantly higher than control values by Student’s ttest, p < 0.05, except cytoplasmic Na in the presence of FCCP, which was lower than control.

**Significantly higher than control values by Student’s ttest, p < 0.01.

***Not significantly different from zero. The actual concentration must be positive, but negative experimental values, reflecting statistical fluctuations, sometimes occur for populations with concentrations effectively below the limit of detection.