TY - JOUR
T1 - Atrial natriuretic peptide and cGMP activate sodium transport through PKA-dependent pathway in the urinary bladder of the Japanese tree frog
AU - Yamada, Toshiki
AU - Matsuda, Kouhei
AU - Uchiyama, Minoru
N1 - Funding Information:
Acknowledgements We thank Dr. K. Narita of Iwate Medical University for the technical assistance on the patch-clamp experiment. This work was supported in part by a research grant from Toyama University.
PY - 2006/3
Y1 - 2006/3
N2 - The effects of atrial natriuretic peptide (ANP) and cGMP on transepithelial ion transport were examined in the urinary bladder of the Japanese tree frog, Hyla japonica, using Ussing chamber voltage-clamp and whole-cell patch-clamp techniques. When the bladders were exposed to 4.4×10-11 to 10-6 M ANP or 10-7 to 3×10-4 M 8-Br-cGMP, both the transepithelial potential difference (PD) and the short-circuit current (Isc) were significantly increased in a concentration-response manner. The cGMP-dependent responses were inhibited in a Na+-free bath solution and in the presence of amiloride. The cGMP-dependent increases in Isc were significantly inhibited by specific PKA inhibitors (5×10-7 M KT-5720 and > 10-5 M H-89), but not by a specific PKG inhibitor (5×10-7 M KT-5823). ANP-dependent increases in Isc were also significantly inhibited by KT-5720. In the patch-clamp study, ANP and cGMP significantly increased in inward currents involving Na+ uptake. These results suggest that a cross-talk mechanism exists between cAMP and cGMP signaling pathways, which leads to Na+ transport in the frog urinary bladder. In addition, the cGMP-dependent increases in Isc were partially inhibited by 10-4 M l-cis-diltiazem, a specific inhibitor of cyclic nucleotide-gated (CNG) channels. These results also suggest a relation between CNG channels and the cGMP-dependent increases in Na+ absorption of the frog urinary bladder.
AB - The effects of atrial natriuretic peptide (ANP) and cGMP on transepithelial ion transport were examined in the urinary bladder of the Japanese tree frog, Hyla japonica, using Ussing chamber voltage-clamp and whole-cell patch-clamp techniques. When the bladders were exposed to 4.4×10-11 to 10-6 M ANP or 10-7 to 3×10-4 M 8-Br-cGMP, both the transepithelial potential difference (PD) and the short-circuit current (Isc) were significantly increased in a concentration-response manner. The cGMP-dependent responses were inhibited in a Na+-free bath solution and in the presence of amiloride. The cGMP-dependent increases in Isc were significantly inhibited by specific PKA inhibitors (5×10-7 M KT-5720 and > 10-5 M H-89), but not by a specific PKG inhibitor (5×10-7 M KT-5823). ANP-dependent increases in Isc were also significantly inhibited by KT-5720. In the patch-clamp study, ANP and cGMP significantly increased in inward currents involving Na+ uptake. These results suggest that a cross-talk mechanism exists between cAMP and cGMP signaling pathways, which leads to Na+ transport in the frog urinary bladder. In addition, the cGMP-dependent increases in Isc were partially inhibited by 10-4 M l-cis-diltiazem, a specific inhibitor of cyclic nucleotide-gated (CNG) channels. These results also suggest a relation between CNG channels and the cGMP-dependent increases in Na+ absorption of the frog urinary bladder.
KW - Atrial natriuretic peptide
KW - Frog urinary bladder
KW - Na transport
KW - cAMP-dependent protein kinase
KW - cGMP
UR - http://www.scopus.com/inward/record.url?scp=33644619837&partnerID=8YFLogxK
U2 - 10.1007/s00360-005-0041-z
DO - 10.1007/s00360-005-0041-z
M3 - 学術論文
C2 - 16320061
AN - SCOPUS:33644619837
SN - 0174-1578
VL - 176
SP - 203
EP - 212
JO - Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
JF - Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
IS - 3
ER -