Fig. 3.
Bar graph of Isc experiments in primary culture monolayers of SRG tubular epithelial cells. Both CNP-and forskolin-induced chloride secretion were inhibited to a similar extent by the nonspecific protein kinase inhibitor staurosporine (1 μM) and the specific PKA inhibitor H-89 (50 μM) but were insensitive to the inhibitor of both isoforms of cGMP-dependent protein kinase H-8 (100 μM). Filter-grown monolayers of SRG cells were preexposed to the PK inhibitors (added to the mucosal and serosal bath of the Ussing chamber) for 30 min before the addition of the secretagogues. Values are percentage inhibition of the CNP (0.5 μM) or forskolin (1 μM) induced Isc response averaged from 4 independent experiments ± SE. **P < 0.01, compared with the Isc response without inhibitor; n.s, not significantly different from the Isc response without inhibitor.