Angiotensin II induces phosphorylation of the thiazide-sensitive sodium chloride cotransporter independent of aldosterone.
We studied here the independent roles of angiotensin II and aldosterone in regulating the sodium chloride cotransporter (NCC) of the distal convoluted tubule. We adrenalectomized three experimental and one control group of rats. Following surgery, the experimental groups were treated with either a high physiological dose of aldosterone, a non-pressor, or a pressor dose of angiotensin II for 8 days. Aldosterone and both doses of angiotensin II lowered sodium excretion and significantly increased the abundance of NCC in the plasma membrane compared with the control. Only the pressor dose of angiotensin II caused hypertension. Thiazides inhibited the sodium retention induced by the angiotensin II non-pressor dose. Both aldosterone and the non-pressor dose of angiotensin II significantly increased phosphorylation of NCC at threonine-53 and also increased the intracellular abundance of STE20/SPS1-related, proline alanine-rich kinase (SPAK). No differences were found in other modulators of NCC activity such as oxidative stress responsive protein type 1 or with-no-lysine kinase 4. Thus, our in vivo study shows that aldosterone and angiotensin II independently increase the abundance and phosphorylation of NCC in the setting of adrenalectomy; effects are likely mediated by SPAK. These results may explain, in part, the hormonal control of renal sodium excretion and the pathophysiology of several forms of hypertension.
van der Lubbe
Nils
N
Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands.
Lim
Christina H
CH
Fenton
Robert A
RA
Meima
Marcel E
ME
Jan Danser
Alexander H
AH
Zietse
Robert
R
Hoorn
Ewout J
EJ
D000315:Adrenalectomy; D000450:Aldosterone / Q000494:pharmacology* / Q000502:physiology; D000704:Analysis of Variance; D000804:Angiotensin II / Q000008:administration & dosage / Q000494:pharmacology* / Q000502:physiology; D000818:Animals; D051399:Aquaporin 2 / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D053503:Epithelial Sodium Channels / Q000378:metabolism; D007686:Kidney Tubules, Distal / Q000502:physiology*; D008297:Male; D023421:Models, Animal; D010766:Phosphorylation / Q000187:drug effects*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000652:urine; D049992:Sodium Chloride Symporters / Q000187:drug effects* / Q000378:metabolism
D051399:Aquaporin 2; D053503:Epithelial Sodium Channels; D049992:Sodium Chloride Symporters; D000804:Angiotensin II; D000450:Aldosterone; D012964:Sodium; C116037:PAS domain kinases; D017346:Protein Serine-Threonine Kinases