Calcium glycerophosphate preserves transepithelial integrity in the Caco-2 model of intestinal transport

Table 1 Baseline changes in trans epithelial electrical resistance and mannitol flux from time 0 to 4 h

Treatment	Rate of TEER change	Rate of mannitol flux
	% per hour	dpm per hour
Control	0.69 ± 0.11a	28 ± 4
Vehicle	-0.24 ± 0.32c	19 ± 4
1 mmol/L CGP	0.80 ± 0.14a	31 ± 4
100 μmol/L CGP	0.28 ± 0.13	19 ± 3
10 μmol/L CGP	-.09 ± 0.37	21 ± 5
1 μmol/L CGP	0.48 ± 0.23c	31 ± 6

Trans epithelial electrical resistance (TEER) was significantly lower in vehicle (0.1% citric acid) treated cells, an effect that was reversed by calcium glycerophosphate (CGP) in a concentration dependent fashion.

^aP < 0.05 vs vehicle;

^cP < 0.05 vs control. Rate of TEER and mannitol flux were calculated by taking the slope of the linear portion of the TEER or mannitol flux vs time curve (0 to 4 h). dpm represents disintegrations per unit time. Each value represents the results of three independent experiments. Data is expressed as mean ± SE.

Table 2 Effect of hypoxia on the rate of trans epithelial electrical resistance loss and mannitol flux during the first three hours of hypoxia

Treatment (hypoxia)	Rate of TEER loss	Rate of mannitol flux
	% per hour	dpm per hour
Control	19.4 ± 1.31	162 ± 27
1 mmol/L CGP	6.79 ± 1.12b	19 ± 4b
100 μmol/L CGP	9.67 ± 1.42b	39 ± 3b
10 μmol/L CGP	10.61 ± 1.86b	35 ± 3b
1 μmol/L CGP	12.2 ± 1.56b	49 ± 7b

Calcium Glycerophosphate (CGP) treatment reduced both parameters in a dose-dependent fashion.

^bP < 0.001 vs hypoxia alone. Each value represents the results of three independent experiments. dpm represents disintegrations per unit time. Data is expressed as mean ± SE.

Table 3 Rate of trans epithelial electrical resistance loss and mannitol flux during the first four hours (mannitol flux) or 10 h (trans epithelial electrical resistance) following cytokine stimulation

Treatment	Rate of TEER loss	Rate of mannitol flux
	% per hour	dpm per hour
Control	0.064 ± 0.38b	28 ± 3b
Cytokine	2.1 ± 0.31	54 ± 1
Cytokine + 1 mmol/L CGP	0.76 ± 0.24b	4 ± 1b
Cytokine + 100 μmol/L CGP	0.87 ± 0.32b	10 ± 1b
Cytokine + 10 μmol/L CGP	1.4 ± 0.28b	13 ± 1b
Cytokine + 1 μmol/L CGP	2.4 ± 0.34	16 ± 2b

Calcium glycerophosphate (CGP) treatment reduced both parameters in a dose-dependent fashion.

^bP < 0.001, vs cytokine alone. Each value represents the results of three independent experiments. dpm represents disintegrations per unit time. Data is expressed as mean ± SE.

Table 4 Effect of calcium glycerophosphate on α-gliadin peptide 31-55 induced mannitol flux

Treatment	Mannitol flux (dpm/h)	% of control
Control	21 ± 1	100%
Peptide	36 ± 1b	171%
Peptide + 1 mmol/L CGP	28 ± 1b	133%
Peptide + Cytomix	39 ± 3b	186%
Peptide + CGP + Cytomix	32 ± 1b	152%

^bP < 0.01 vs control; each value represents the mean of 3 independent experiments. dpm represents disintegrations per unit time. Data is expressed as mean ± SE.