Table 3.

Unidirectional and net fluxes of Na* and Cl⁻ across distal colon of rats pre-exposed to cholera toxin (CT):effect of butyrate and bumetanide

	G	ISC	JNa,ms	JNa,sm	JNa,net	JCl,ms	JCl,sm	JCl,net
Control
Post-CT	10.2 ± 0.5	3.0 ± 0.2	6.2 ± 0.5	7.5 ± 0.4	−1.3 ± 0.3	13.7 ± 1.0	16.7 ± 1.0	−3.0 ± 0.4
Bumetanide	11.1 ± 0.5§	1.8 ± 0.1‡	7.4 ± 0.2*	5.1 ± 0.3§	2.3 ± 0.3§	14.5 ± 0.5n.s.	10.2 ± 0.5§	4.3 ± 0.3§
Butyrate
Post-CT	8.3 ± 0.3†	1.0 ± 0.6§	10.4 ± 0.7§	4.1 ± 0.5§	6.3 ± 0.6§	19.8 ± 0.8§	13.2 ± 0.6†	6.6 ± 0.9§
Bumetanide	8.3 ±0.2n.s.	0.5 ± 0.1§	9.9 ± 0.6n.s.	3.8 ± 0.6n.s.	6.1 ± 0.8n.s.	20.2 ± 0.9n.s.	14.1 ± 0.6n.s.	6.1 ± 0.6n.s.

for both control and butyrate studies,values shown are means ±s.e.m. of nine matched tissue pairs. Bumetanide was always added to the serosal reservoir after three 15 min flux periods. See Table 1 for further details and definitions.