A Signaling Pathway for Stimulation of Na+ Uptake Induced by Angiotensin II in Primary Cultured Rabbit Renal Proximal Tubule Cells

Journal of Veterinary Medical Science

Ho Jae HAN¹  Hyun Ju KOH¹  Soo Hyun Park¹ 

[1] Department of Veterinary Physiology, College of Veterinary Medicine, Hormone Research Center, Chonnam National University, Kwangju, 500-757 Korea

关键词: angiotensin II;    Na+/H+ antiport;    primary proximal tubule cell;    protein kinase C;   

DOI  :  10.1292/jvms.61.135

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

References(33)Cited-By(3)The aim of the present study was to examine the signaling pathways for a low dose of angiotensin II (ANG II) on Na+ uptake of primary cultured rabbit renal proximal tubule cells (PTCs) in hormonally defined serum-free medium. The results were as follows; ANG II (10-11 M) stimulated the proliferation of PTCs. 10-11 M ANG II stimulated Na+ uptake by 20%, whereas 10-9 M ANG II inhibited it by 20% (p<0.05). The stimulatory effect of 10-11 M ANG II on Na+ uptake was inhibited by amiloride (10-3 M) and by losartan (ANG II receptor subtype 1 antagonist, 10-8 M) but not by PD123319 (ANG II receptor subtype 2 antagonist, 10-8 M). Pertussis toxin (PTX, 50 ng/ml) prevented the ANG II-induced stimulation of Na+ uptake (p<0.01). 8-Bromoadenosine 3', 5'-cyclic monophosphate (8-Br-cAMP, 10-6 M) did not affect Na+ uptake. SQ 22536 (adenylate cyclase inhibitor, 10-6 M) also did not change the ANG II-induced stimulation of Na+ uptake. ANG II did not stimulate cAMP production. In contrast, 12-O-tetradecanoylphorbol-13-acetate (TPA, 0.01 ng/ml) produced significant increase in Na+ uptake. When ANG II and TPA were added together to the PTCs, there was no additive effect on Na+ uptake. Staurosporine (calcium-dependant protein kinase C inhibitor, 10-6 M) led to a complete inhibition of ANG II-induced stimulation of Na+ uptake. ANG II-treatment resulted in a 26% increase in total protein kinase C (PKC) activity. However, 10-11 M ANG II did not change [Ca2+]i mobilization and [3H]-AA release while 10-9 M ANG II increased both of them. In conclusion, the PTX-sensitive PKC pathway may be the main signaling cascade in the stimulatory effects of low dose of ANG II (10-11 M) on Na+ uptake in the primary cultured rabbit renal proximal tubule cells in hormonally defined serum-free medium.

【 授权许可】

Unknown