Transcriptional regulation of sodium transport by vasopressin in renal cells.
We have examined whether arginine vasopressin (AVP) can induce a long-term modulation of transepithelial ion transport in addition to its well known short-term effect. In the RCCD1 rat cortical collecting duct cell line, an increase in both short-circuit current and 22Na transport was observed after several hours of 10(-8) M AVP treatment (a concentration above the in vivo physiological range). This delayed effect was partially prevented by apical addition of 10(-5) M amiloride and was blocked by 10(-6) M actinomycin D and 2 x 10(-6) M cycloheximide. The amounts of mRNA encoding the alpha1 (not beta1) subunit of Na+/K+-ATPase and the beta and gamma (not alpha) subunits of the amiloride-sensitive epithelial Na+ channel were significantly increased by AVP treatment. The increase in mRNA was blocked by actinomycin D, not by amiloride, suggesting a Na+-independent increase in the rate of transcription of these subunits. The translation rates of the alpha1 subunit of Na+/K+-ATPase and the beta and gamma subunits of the rat epithelial sodium channel increased significantly, whereas the translation rates of the other subunits remained unchanged. Finally, the number of Na+ channels present in the apical membrane of the cells increased, as demonstrated by enhanced specific [3H]phenamil binding.
Djelidi
S
S
INSERM, Institut Fédératif de Recherches "Cellules Epithéliales," Faculté de Médecine Xavier Bichat, 16, rue Henri Huchard, 75870 Paris Cedex 18, France.
Fay
M
M
Cluzeaud
F
F
Escoubet
B
B
Eugene
E
E
Capurro
C
C
Bonvalet
J P
JP
Farman
N
N
Blot-Chabaud
M
M
D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D001692:Biological Transport; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D053503:Epithelial Sodium Channels; D007668:Kidney / Q000378:metabolism*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D012964:Sodium / Q000378:metabolism*; D015222:Sodium Channels / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D014158:Transcription, Genetic
D053503:Epithelial Sodium Channels; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D015222:Sodium Channels; D001127:Arginine Vasopressin; D003609:Dactinomycin; D000584:Amiloride; D003513:Cycloheximide; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase